Zuru XShot Piston Pump - Bolterized

It's a quick and dirty mashup of models made by people more talented than me. The objective is to make what's quite an awkward looking blaster look a little more like a Warhammer 40k Bolter. 
 

The picatinny rails are attached with 4x M3x10 screws. Remove the collet, slide on the bracket, replace the collet, attach the rails to the bracket and shroud. Slide the battery grip onto the bottom rail, put the peg through the holes to hold the grip onto the rail. You'll want to make sure the pin fits in the holes easily enough to come out again when you want to change the battery. In order for this to make sense you'll need to reroute the battery cable, and extend it a little. Route it along the top of the shell inside the moulded rail. You'll need to make a few little cuts so it'll go where it needs to. Cable come out just under the barrel, right into the battery box. There's a stock delete plug too. 

I'm sure the files are a mess technically; I'm afraid I've not got past Tinkercad, so whatever happened, happened. Thanks to everyone who provided the original files, you got me 99% of the way there.