Page 28 of an undated Savage/Stevens/Fox component parts catalog, the has the only reference of the 56C that I can find outside of GPC. The wording suggests that the 56c belongs in the same family as the Savage 4c, 4cd, 4d, 4e, 4m, 84c, 84cd, 84d, and 84e bolt action clip fed .22s.

If you email your USPS mailing address to me at remguy260cox.net, I can mail you a copy of that page.

Jeff