The Colt "J" frame was Colt's replacement for all the older revolvers they could no longer afford to sell due to the extensive hand fitting required to assemble them.
The replacement was the Colt "J" frame made as the Trooper Mark III, Lawman Mark III, Metropolitan Police, and Official Police Mark III.,
The Lawman Mark III was made from 1969 to 1983, and there was a slightly improved Lawman Mark V made in 1984 and 1985.
The Lawman was available in a 4" un-shrouded barrel and a 2" barrel rounded butt version.
The 2" Lawman early versions also had an un-shrouded, exposed ejector rod, but later production models had a heavy shrouded barrel that looks like a giant Detective Special.
The guns were available in bright blue, bright nickel, and satin electroless nickel also known as "Coltguard".
These are extremely strong, high quality guns that are a definite step above most anything made today.
Master gunsmith Jerry Kuhnhausen considered them to be the strongest medium frame double action revolvers ever made.
The only possible weakness is that the guns shouldn't be dry fired without snap caps, since the firing pin "might" break, and this REQUIRES a trip back to Colt for replacement. This requires special equipment to prevent damaging the frame, so it's a factory ONLY job.
Other than that, the Lawman is a tank.