Help identifying RCA XL-100 year

[mwplefty]

I think that it's a 1977-1979. The tabletop set in my avatar is a 1974 XL-100, but it has knobs. I can't think of an XL-100 before 1977 that had push-button tuning. I just remember that the Colortrak was favorable to the XL-100 by the 1980's.