Places to start include the Blue Book of Gun Values, The Book of Colt Firearms and you can always call Colt.
about 1951
Colt
That Colt super .38 was made in 1948.
Proofhouse.com has Colt sn data
You will have to call Colt
Manufactured in 1968
Manufactured in 1930.
1957
Proofhouse.com has Colt sn data
your colt official police was produced by colt in 1933.
You will have to call Colt
Proofhouse.com has Colt sn data.