I have an Ampeg SVT810 that I have positively identified to be 1979 20th week. . However the horible paper tag on the back of this cab that contains a serial number has apparently weathered so that only a 2 is visible on the very end. . My question is, is there any other way to identify what model number or name this cab has? I dont know if this helps but it is a slant back cab?!?!?