A Land Far Away

So, maybe a stupid question, but I'm trying to tip-toe into the toolset and wonder...

Is there a way to get appearance model parts/components from one type of item ported over for use in another type of item? For instance, how can I build a sword, but port in the model for the katana handle instead of using one of the traditional handles available for the type of sword I'm creating (longsword, shortsword, etc)?

That would need new haks. There are only so many valid appearances per item type, you'd have to have someone doing work in a modelling program and then altering the haks to go "look for all those new models" to add new valid combinations. It might be found that there's a lot of gaps and things not connecting or looking right so I guess lots of modelling trial and error... again, third party tools nothing to do with the toolset, to make kind of "toolset useful" content.

So you're not really missing anything, not a dumb question.