Try proofhouse
By the serial number. Go to proofhouse .com
Go to proofhouse .com with Colt serial number to find the date of manufacture.
If your Colt detective special had the prefix D in front of the serial number 956808 then it was made in 1967. According to Proofhouse, 1966 started with D900101. As far as I know they were made at the Colt Mfg. Co in Hartford, CT. See the Proofhouse link below.
A small revolver that was made in Belgium. ELG is the proof mark for the Belgian proofhouse at Liege, Belgium. All guns made in Belgium were sent to the proofhouse, to be tested (proved) by inspection, and firing with a special high powered cartridge (proof load).
100-1000 USD and up depending on specifics. proofhouse has sn's
The first serial number for 1972 was 3557386. There were 249,114 made that year. Source: Proofhouse website.
go to proofhouse .com and click colt serial numbers,this will tell you the age of your colt.
100-1000 USD depending on specifics. Try proofhouse for the sn.
Proofhouse can often help when searching for this kind of data on a firearm. Please see "related links" below this answer.
For the Colt police positive .38 revolver, proofhouse,com shows 1907 as the production year.
Don't have the exact date as proofhouse .com records only goe up to 1978., but the mustang was only produced between 1986 to 1997