I am looking for a service manual for an RCA CRT TV set (24 inch floor console) made in April of 1978. The model designation shown on its front panel apparently is confused with the same number for a later model of RCA TV set made by Thomson. This model number is XL-100, but an RCA model number on a product label on the back of the 1978 set is GC-684 L, with a serial number of 814571255. Does this service manual still exist somewhere?