Rich, if you look through the various photos of McIntosh tuners and preamps, you can see some of the "gold" ones on Berner's great website.
http://www.berners.ch/McIntosh/en/Frame_McIntosh.htm
If I had to characterize McIntosh appearances, there have been four phases:
1)1949 to 1955 - original gear which was mostly green in appearance.
2) 1955 to 1962 - mostly gold and black highlights
3) 1962 to 1971 - two tone, light gold/silver and black
4) 1972 to today - mostly black with silver/gold accents.
Of course, the above is a generalization, there were some two-tone amps that went well into the '80s. Are you thinking of the C20 preamp and MR65 tuner for example, or even further back to the MR55 tuner days.
Gold seem to be really popular in the '50s when you look at Scott, Pilot and Fisher vintage gear.