No such model in the Colt line.
about 1976
Around 1885.
After 1978.
Go to www.proofhouse.com my reference book says 1876
You will have to call Colt
It tells the year of manufacture of a Colt.
call colt factory for date of manufacture at: 1-800-962-2658
you will have to call Colt to find out.
it ain't worth a monkeys left ball
Colt data at Proofhouse.com
1970
Your colt was made in 1956.