Period from about 1969 to 1983
It was produced in 1971,
@1976
1976
50-450 usd
value depends on overall condition.....................
The Lawman mk III Colt 357 mag is valued at $1,000 in excellent condition. Good condition value is $800.
100-300 USD depending on condition
value depends on overall condition..................
I just put a Lawman Mk. III on layaway at a local gun shop. It was selling for $650, but the guy gave it to me for $599. It's in great condition, as far as I can tell.
Proofhouse.com has Colt sn data.
http://www.thefiringline.com/forums/showthread.php?t=313508 This forum discusses your Colt Lawman and it's variations, I hope this helps, there is a web site with a hot link listed in this string and also the number for Colt so you can ask them directly, which is 800-962-colt the web site is http://proofhouse.com/colt/
What you have is a Colt Mark III series Lawman in 357 magnum that dates to 1969. Value depends on other things also. Do you have the box, manual, papers that came with it? What barrel length? What is the finish (blue or nickel)? A very broad range would be 250-600.