Denix has. They offer their Mauser with plastic and also with wooden grips.
For most of the Solo blasters plastic would be more accurate, as the used MGCs had plastic grips also.
Same thing as with painting them, a lot of builds are wrong ..... by not knowing it better or due to personal preferences over movie accuracy - check the facts for the specific gun you want to build before you trust someones sayings. And then make your own educated decision.