You would probably have to have a set manufactured because replacements are not available. You can try: Numerich gunpartscorp.com
Jack First jackfirstgun.com
Bob's Gun Shop gun-parts.com If they don't have anything, the cost of manufacture will far exceed the value of the gun.
You will need to provide a DETAILED descripton of ALL markings, gauge, barrel length, forearm, butt stock, etc..
Requires in person examination.
I need a stock for a 16 gauge WP Wonder shotgun singleshot?
This weapon will need to be appraised and compared against known samples.
No
Try Mid West Gun Works.
Start with gunpartscorp.com - they sometimes have Hopkins & Allen parts
stock is standard american walnut, no stain.
Try gun shop, gun shows, garage sales, want ads, e-gunparts.com
Try e-gunparts.com
Remove stock from shotgun
Any mossberg 500 stock will fit