http://www.histandard.info/manuals/sears/rfrifles/index.html note that there are seveal versions of the model 31
J.C. Higgins is an old brand name used by Sears.
I have quite a few. email@example.com
I am not sure about the diagram,but I would check at numrich gun parts corp. first for the parts you need.
Gun Shops And Internet!
try this-------http://www.e-gunparts.com/--I know they have parts--Vail
Send me your email & I'll send you a scan of the diagram. USDF
theres a website j.c. Higgins model 88 has the exploded view with parts list
Made by Savage. We have parts. firstname.lastname@example.org
You can try Numrich gun parts, ( e-gunparts.com )
e gun parts.com