I haven't done a shotgun skin yet, and I was browsing GB's model section and found Revtiva/Hemingway's M590. I decided to use it with some neat animations by kopter from this CS:S release:
Textures are chopped and (kinda) bumped up, I still can't bake light yet so it may look a bit bad but I found it good in-game. PeeWees are included and use a much lower poly optimized model.
Note: For the best result type these 2 commands in the console before joining/creating a server:
gl_max_size 1024 gl_round_down 0
I hope you like it. Have a very safe and productive day!