Handle
The final part of the holder is the handle. Like the other areas I used cardboard to reinforce things and removed the tabs.
The holder is one wrapper piece with two recessed detail pieces. Here is how it looks from the inside. The previous pieces make up the upper detail.
The top and bottom pieces of the handle.
And here is the final subassembly. This is a solid piece and I'm really happy with how it came out. It's the best work I've done on this whole model so far.
And lastly, here it is attached the gun.