it's not too hard to modify the .sma file by changing the custom weapons. but .... nice.
an advice using this plugin is better [ZP] Golden Ak 47 [Added w_ model]
also. there is another nice plugin, that needs for some models, if we want to change its original weapon: the dual MP5 Mod.
I already have some dual weapons (look here), if someone can find others, then share them please.