Question, and it's probably been asked before, but is there a way to make mod kits work for custom weapons? Is it something that can be easily implemented or will it require a painstaking amount of work?
As for the possibility, yes it is. But is it easily implemented? I say it's not.
I made my personal tweak to this mod, so Wanda can have unique looking http://img145.imageshack.us/img145/2622/gunsnn3.jpg.
To doing this, you have to tweak nif files via nifskope, then esp with GECK.
However, unless you understand what needed to do in both nifskope and GECK, it's a painstaking amount of work.
It's took me around 5 hours to "just changing looking of already implemented weapon".
So, to adding custom weapon which is not implemented in default WMK, Im afraid you will need quite amount of knowledge with GECK, including scripting.
With this reason I really appreciate Antistar's work. Just allowing customise vanilla weapons are already tough work.
And I decided to not request anymore about adding something new, it's really hard to do so.
#EDIT - Typos