Are you sure it is not 130W, mono? I don't think it's stereo.
It looks an awful lot like a Peavey 260C, which is 130W mono @ 4ohms.
BTW, for comparison, the 260C schematic I have is dated 8/30/78, revised '86.
It also looks like it succeeded the Peavey Standard, this thing: Peavey Standard