You will need to call Colt.
If you call Colt, they will tell you.
made about 1928......................
It was made in 1966.
about 1904
Your colt was made in 1956.
Proofhouse.com has Colt sn data. If not there, call Colt.
Your colt single action army was made in 1906.
1903
1919
about 1883
made about 1877
With that serial Numbe, it was made in 1900.