Hey I think this might go better in the mod suggestions section but theres always the Couriers Cache for more homemade DIY guns http://www.nexusmods.com/newvegas/mods/49531/? or possibly the homemade PPSH? http://www.nexusmods.com/newvegas/mods/50855/?
Also as for a relatively new mod http://www.nexusmods.com/newvegas/mods/60424/ however Im not sure if this affects appearance (I think it does?) or if its just stat based.
Hopefully one of those catches your fancy!