Gun Photoshop help please, making 2 pictures look like one

[SocialistSlayer]

I just got this PS90 (top picture), but when i took the pretty cool bottom picture I didnt have it, so i was wondering if somebody with good photo shop skills could possibly make it look like the PS90 is part of the other picture making it look natural, and proportional.

i would guess making it vertical, and on the left side of the picture would be the best bet.

So if anybody could do that it would be much appreciated.

 

edit: or just use this image instead of the top photo PS90, since this one is higher quality

edit 2x:

more gun porn, just for fun. featuring my brothers stuff.

edit 2: brother just put my guns in new pelican case. plus more pictures.