There is no such thing as a 70 series commander. It applies to the collet bushing that was made in the 70s. Your commander was mfg. sometime in the 70s without the that type of bushing.
No way to answer without a serial number.
The best I can do is say that your colt Combat commander series 80 was made from 1983-1996.
my guess would be late 1970's.................
How can I find out what year Colt Combat Commander Mark 4 Series 80 was made?
You will have to call Colt to find out.
Late 1980s or early 1990s
According to proofhouse.com ,a Colt combat commander with that serial number was manufactured in 1977. The 1978 series started with 70SC57900.
Published data does not go that high. You will need to call Colt
You will have to call Colt. Published serial numbers stop at 1978
That colt commander with serial # 39487LW was produced in 1959. (39450LW-41500LW) mfg date is 1960, not sure if '70 or '80
You need to call Colt to find out. That sn goes beyond published data.
around 1980.