Try numrich gun parts corp.They can be found on the web.
Try www.gunpartscorp.com
Numrich Arms should have them.
Umarex.com just rebuilt my model 815 excellent service
i found a small list of parts at numrich guns and parts
From Daisy. You can request a manual by email- info@daisy.com
www.urban-armory.com
Get your model number and put it into a google search like this "snapper model *******" You should get a few companies that list the parts for it.
Try contacting Whirlpool who is the parent company of Roper. They may have a parts manual or a list of local dealers who may be able to help you. find parts for your particular model Roper.
You can find a list of body parts in many medical books. Gray's anatomy is one such book that has the parts of the body listed inside.
It is a Stevens 940B. I have the schematic. sales@countrygunsmith.net
Send me your email & I'll send you a scan of the manual & exploded view.
theres a website j.c. Higgins model 88 has the exploded view with parts list