Value of a gun is based on make, model, and condition. You gave us one of the three factors we need. You can contact Colt Customer Service for dates, but there is not a generally accepted public database.
value depends on overall condition.....................
your colt trooper mkIII was made in 1978.
Do you have a colt python?
0-500 usd
50-500 usd
about 1975
The value of a 357 colt Python v 20978 is 1962 The value will depend on the condition and additional options, but Pythons are very valuable. They can go for thousands of dollars.
1000 USD, you will have to call Colt
value depends on overall condition...................
about $600 to $900
50-450 usd
The Lawman mk III Colt 357 mag is valued at $1,000 in excellent condition. Good condition value is $800.