I am not sure,but I would start my search at numrich gun parts corp.They can be found on the web.
On net for $399 + in excellent condition.
To answer your question, we need to know the Model 322A WHAT? Make, and type of firearm.
A FEW parts are available from gunpartscorp website.
I have seen the model 322A sell from as much as 290.00 to 315.00 although value in schwing 2005 catalog was 175 in exc condition 125 in v.g.
NUMRICH HAS PARTS FOR THE STEVENS 66B
Try any gunsmith. Try Savage Arms. They have an website. e-gunparts.com (Numrich)
Stevens is owned by Savage, but manuals may not be available due to age. Savage Customer Service is (800) 370-0708. A parts diagram is available on line at the gunpartscorp website.
you can find parts for your Stevens at bob`s gun parts .com
Yes, if they are available and you are not violating any laws. Try e-gunparts.com
where can i find replacement parts for a 22 caliber Stevens modle987
webdept@gunpartscorp.com has many parts and breakdown books for many Stevens rifles and shotguns.
The Western Field mod SD57 was manufactued by Stevens as their model 87. Limited parts are available from Gunpartscorp.com. Look around for other sources.