When you release the catch to the cylinder you should see the serial number stamped on the crane at the swivel.
A Colt official police special with that serial number ws made in 1947.
Your Colt official police special was made in 1956.
Your colt official police was made by colt in 1940.
That Colt official police special was made in 1968.
Colt official police with that serial number was produced in 1927
A Colt official police with that serial number was made in 1948.
Around 1941 for Colt official police
Your colt official police was made in 1967.
have to guess about 1914
50-400usd
1960
You will have to call Colt with the sn to find out.