What Mossberg rifle are you talking about here? The new Plinksters made in Brazil that sell for around $100?
Or are you asking about the vintage Mossberg rifles made for the '30 through the '70's?
And what exactly do you want besides a stock?
If you want to play stick to the 1022 or even a Marlin 60. There aren't many aftermarket things for anything like there is for the 1022.
I don't think there ever will be a market for custom parts and stocks for the new Mossberg Plinksters. They serve a purpose, cheap plinking or beginnner rifles. But Mossberg does offer a few with that silly muzzle brake that looks like it should be on a 50BMG.