Oh dear, how did I miss the hammer? I'm usually quite nitpicky about those things.
Either way, a couple of these problems will be easily solvable once the gun is textured. (This is probably going to be going into city 17: episode one)
I'll make sure to fix slide catch, I don't think we could fix that with a texture.
Edited: Added slide catch, slide is not a part of the frame, this will be fixed by texturing, odd space is fixed, empty space is shell ejection (i assume), barrel weight connected problem will be fixed, again, with texturing. (I'll be sure to show off the pistol when it's textured!