You will have to call Colt to find out.
Manufactured in 1975.
If that is the colt combat commander, it was manufactured in 1962.
Manufactured in 1978.
Made in 1976.
The best I can do is say that your colt Combat commander series 80 was made from 1983-1996.
Made in 1973.
made about 1978 or 1979
about 1978
If not listed at Proofhouse.com, call Colt
1970
I would guess about 1980....................
my guess would be late 1970's.................