All great points. The 4000t is not an option as it doesn’t have the auto correlation and peak unlimiter which I need for an all analog tape and vinyl system.
However it does look like there were two “versions” of the c4000 itself. Both have the time day output/amps, SH, and AC/PU.
The earlier Version 1 has a 35/50 time delay switch and has a phono 1 and phono 2 inputs. It has the champagne faceplate color. Probably manufactured from 1979 thru 1982.
Version 2 has a darker faceplate , almost black , with a gun metal outer plate. It has the shorter 15/35 time delay and