I saw a stock set for a 16 on eBay... but they wanted a half of what you paid for the gun for it.
I've seen a couple on ePay as well. Probably the same ones.
FWIW, I've been working on the stock of this 37 for a few weeks now. Took me a while, but I found a small chunk of walnut with similar grain and have it attached to the old portion of the stock. Haven't touched it in a while but the next step is to put it on the edge sander and try and match up the stock lines. Patience is a virtue .. . . .