Buy parts for 410 Stevens model 67 pump shot gun.
I have parts for that model. email@example.com
Try your local gunsmith. The Riverside is a Stevens shotgun. If you can find out which model it is, you can probably find the wood at Numrich Gunparts
numrich gun parts
it is a Stevens, parts are interchangeable...
I had to buy a gun to break. Don't have it now. I do have a parts list from Stevens i.e. exploded diagram. Not much use unless you can source a second hand gun or part.
Have you tried e-gunparts.com?
Check on Numrich gun parts corp website.
Start your search at Numrich gun parts corp.They can be found on the web.
Numrich Arms has parts for the 311