I just got a Weaver pivot base & rings from fleabay. Weaver base #193, for Remington Model 4, 6, 7400, and 7600.
While I have several #162 sets for Remintgton 742's, 760's, this is the first #193 base I have seen.
I really wasn't sure if Weaver ever made a pivot base for a 7600 as I lost my old pivot base charts from Weaver when my last computer crashed.
Anyways, glad to have found one, just in case I happen to run across a nice 7600.