Not sure if you saw, but I have this in the latest build. I'm hoping to get that pushed out "soon".
Also I want to thank you again for you mod. It made me realize yet another spot in code where we depend on things that aren't mod friendly. The weapon costume table had a required field of index. That would never work with mods, so I've changed it to be an optional index. You can put in -1 or just leave it blank and the game will put it in there wherever it will fit. That reminds me, I need to increase the max number of costumes allowed per weapon...
I'm glad I could help. If you want, I could upload a newer version of my mod that adds some alternative skins to choose from.