Always. Most recently, I traded into (among other things) a poorly maintained, bubbafied "tacticool" SKS. Way too far gone to be restored, and being a short stocked Yugo, wouldn't fit a man my size if it were. Fortunately, the previous owner still had a "junk box" full of original parts. I'm the process of "de-pimping" it. Lots of mechanical attention and cleaning at first, and now a bit of money spent or set aside each payday to turn it into something clean, accurate, reliable, useful, sensible, and tasteful.
When I'm done, I'll have an assortment of "tactical accessories" to sell or trade to the next Bubba that wants to "sporterize" his SKS. Nothing wrong with that, if it's done intelligently with a specific role in mind... just that what some people want is not what I'd want for myself, obviously.