diff --git a/config.py b/config.py
index d65e2d9f7..4b8f6df8f 100644
--- a/config.py
+++ b/config.py
@@ -24,7 +24,7 @@ saveInRoot = False
 
 # Version data
 
-version = "2.5.0"
+version = "2.5.1"
 tag = "Stable"
 expansionName = "YC120.10"
 expansionVersion = "1.0"
diff --git a/eos/effects/microjumpportaldrive.py b/eos/effects/microjumpportaldrive.py
index 1e5a02569..0b96a9743 100644
--- a/eos/effects/microjumpportaldrive.py
+++ b/eos/effects/microjumpportaldrive.py
@@ -5,5 +5,6 @@
 type = "active"
 
 
-def handler(fit, src, context):
-    pass
+def handler(fit, module, context):
+    fit.ship.boostItemAttr("signatureRadius", module.getModifiedItemAttr("signatureRadiusBonusPercent"),
+                           stackingPenalties=True)
diff --git a/eos/saveddata/drone.py b/eos/saveddata/drone.py
index da4c512f2..4cddbea42 100644
--- a/eos/saveddata/drone.py
+++ b/eos/saveddata/drone.py
@@ -124,6 +124,10 @@ class Drone(HandledItem, HandledCharge, ItemAttrShortcut, ChargeAttrShortcut):
     def dps(self):
         return self.damageStats()
 
+    def changeType(self, typeID):
+        self.itemID = typeID
+        self.init()
+
     def damageStats(self, targetResists=None):
         if self.__dps is None:
             self.__volley = 0
diff --git a/gui/bitmap_loader.py b/gui/bitmap_loader.py
index 2c516b413..042a6674b 100644
--- a/gui/bitmap_loader.py
+++ b/gui/bitmap_loader.py
@@ -85,14 +85,12 @@ class BitmapLoader(object):
             cls.scaling_factor = int(wx.GetApp().GetTopWindow().GetContentScaleFactor())
         scale = cls.scaling_factor
 
-        filenameScaled = "{0}@{1}x.png".format(name, scale)
-        img = cls.loadImage(filenameScaled, location)
+        filename, img = cls.loadScaledBitmap(name, location, scale)
 
-        if img is None:
-            # can't find the scaled image, fallback to no scaling
-            filename = "{0}.png".format(name)
-            img = cls.loadImage(filename, location)
-            scale = 1
+        while img is None and scale > 0:
+            # can't find the correctly scaled image, fallback to smaller scales
+            scale -= 1
+            filename, img = cls.loadScaledBitmap(name, location, scale)
 
         if img is None:
             print(("Missing icon file: {0}/{1}".format(location, filename)))
@@ -100,9 +98,26 @@ class BitmapLoader(object):
 
         bmp: wx.Bitmap = img.ConvertToBitmap()
         if scale > 1:
-            bmp.SetSize((int(bmp.GetWidth()/scale), int(bmp.GetHeight()/scale)))
+            bmp.SetSize((bmp.GetWidth() // scale, bmp.GetHeight() // scale))
         return bmp
 
+    @classmethod
+    def loadScaledBitmap(cls, name, location, scale=0):
+        """Attempts to load a scaled bitmap.
+
+        Args:
+            name (str): TypeID or basename of the image being requested.
+            location (str): Path to a location that may contain the image.
+            scale (int): Scale factor of the image variant to load. If ``0``, attempts to load the unscaled variant.
+
+        Returns:
+            (str, wx.Image): Tuple of the filename that may have been loaded and the image at that location. The
+                filename will always be present, but the image may be ``None``.
+        """
+        filename = "{0}@{1}x.png".format(name, scale) if scale > 0 else "{0}.png".format(name)
+        img = cls.loadImage(filename, location)
+        return filename, img
+
     @classmethod
     def loadImage(cls, filename, location):
         if cls.archive:
diff --git a/gui/fitCommands/calc/fitChangeDroneVariation.py b/gui/fitCommands/calc/fitChangeDroneVariation.py
new file mode 100644
index 000000000..7f277895a
--- /dev/null
+++ b/gui/fitCommands/calc/fitChangeDroneVariation.py
@@ -0,0 +1,39 @@
+import wx
+from logbook import Logger
+
+import eos.db
+pyfalog = Logger(__name__)
+
+
+class FitChangeDroneVariationCommand(wx.Command):
+    """"
+    Fitting command that changes an existing drone into another variation.
+    """
+    def __init__(self, fitID, position, itemID):
+        wx.Command.__init__(self, True, "Change Module")
+
+        self.fitID = fitID
+        self.itemID = itemID
+        self.position = position
+        self.old_drone = None
+
+    def Do(self):
+        return self.change_drone(self.fitID, self.position, self.itemID)
+
+    def Undo(self):
+        self.change_drone(self.fitID, self.position, self.old_drone)
+        return True
+
+    def change_drone(self, fitID, position, itemID):
+        fit = eos.db.getFit(self.fitID)
+        drone = fit.drones[self.position]
+
+        if itemID == drone.itemID:
+            return False
+
+        self.old_drone = drone.itemID
+
+        drone.changeType(itemID)
+        eos.db.commit()
+        # todo: ensure that, whatever type we send in, is actually a variation of the original drone. If not, return False
+        return True
diff --git a/gui/fitCommands/guiMetaSwap.py b/gui/fitCommands/guiMetaSwap.py
index 13497a233..d0c99b8bf 100644
--- a/gui/fitCommands/guiMetaSwap.py
+++ b/gui/fitCommands/guiMetaSwap.py
@@ -12,6 +12,7 @@ from .calc.fitAddCargo import FitAddCargoCommand
 from .calc.fitReplaceModule import FitReplaceModuleCommand
 from .calc.fitAddFighter import FitAddFighterCommand
 from .calc.fitRemoveFighter import FitRemoveFighterCommand
+from .calc.fitChangeDroneVariation import FitChangeDroneVariationCommand
 
 
 class GuiMetaSwapCommand(wx.Command):
@@ -44,7 +45,8 @@ class GuiMetaSwapCommand(wx.Command):
             for x in selection:
                 self.data.append(((FitRemoveFighterCommand, fitID, fit.fighters.index(x)), (FitAddFighterCommand, fitID, itemID)))
         elif context == 'droneItem':
-            raise NotImplementedError()
+            for x in selection:
+                self.data.append(((FitChangeDroneVariationCommand, fitID, fit.drones.index(x), itemID),),)
 
     def Do(self):
         for cmds in self.data:
diff --git a/imgs/icons/10886@1x.png b/imgs/icons/10886@1x.png
deleted file mode 100644
index bc33a7cea..000000000
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diff --git a/imgs/icons/10886@2x.png b/imgs/icons/10886@2x.png
deleted file mode 100644
index 72b667cce..000000000
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diff --git a/imgs/icons/10887@1x.png b/imgs/icons/10887@1x.png
deleted file mode 100644
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diff --git a/imgs/icons/10887@2x.png b/imgs/icons/10887@2x.png
deleted file mode 100644
index 8a85f1071..000000000
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diff --git a/imgs/icons/20959@2x.png b/imgs/icons/20959@2x.png
deleted file mode 100644
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diff --git a/imgs/icons/20966@2x.png b/imgs/icons/20966@2x.png
deleted file mode 100644
index edd49286e..000000000
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diff --git a/imgs/icons/20967@2x.png b/imgs/icons/20967@2x.png
deleted file mode 100644
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diff --git a/imgs/icons/20968@2x.png b/imgs/icons/20968@2x.png
deleted file mode 100644
index dba4a2726..000000000
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diff --git a/imgs/icons/21420@2x.png b/imgs/icons/21420@2x.png
deleted file mode 100644
index fc02b120b..000000000
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diff --git a/scripts/icons_update.py b/scripts/icons_update.py
index 50945ff1c..03bbb9fd7 100644
--- a/scripts/icons_update.py
+++ b/scripts/icons_update.py
@@ -150,6 +150,11 @@ def get_icon_file(res_path, size):
     if not os.path.isfile(fullpath):
         return None
     img = Image.open(fullpath)
+
+    if size > img.size:
+        # if we are requesting a size that is bigger than the source, return None. See #1769
+        return None
+
     img = crop_image(img)
     img.thumbnail(size, Image.ANTIALIAS)
 
diff --git a/service/port/efs.py b/service/port/efs.py
index ef224e850..b572e5376 100755
--- a/service/port/efs.py
+++ b/service/port/efs.py
@@ -83,7 +83,6 @@ class EfsPort():
 
     @staticmethod
     def getPropData(fit, sFit):
-        fitID = fit.ID
         propMods = filter(lambda mod: mod.item and mod.item.group.name == "Propulsion Module", fit.modules)
         activePropWBloomFilter = lambda mod: mod.state > 0 and "signatureRadiusBonus" in mod.item.attributes
         propWithBloom = next(filter(activePropWBloomFilter, propMods), None)
@@ -341,7 +340,7 @@ class EfsPort():
                 # This also covers non-bomb weapons with dps values and no hardpoints, most notably targeted doomsdays.
                 typeing = "SmartBomb"
             # Targeted DDs are the only non drone/fighter weapon without an explict max range
-            if stats.item.group.name == 'Super Weapon' and stats.maxRange == None:
+            if stats.item.group.name == 'Super Weapon' and stats.maxRange is None:
                 maxRange = 300000
             else:
                 maxRange = stats.maxRange