What many people assume to be a stainless Mark III is actually satin electroless nickel, which Colt called "Coltguard".
This looks much like stainless but has the typical slightly yellowish tint of nickel where stainless steel has a "white" tint.
The Lawman Mark III with Coltguard finish shipped with uncoated, color case hardened hammer and blued trigger.
The Colt Lawman Mark III with the 2 inch barrel was made much longer than one year.
The early versions had an exposed ejector rod, which in later production was changed to a heavy, shrouded barrel that looked like a giant shrouded Detective Special barrel.
You're going to have a tough time finding grips for a Mark III with 2 inch barrel. That model was the only gun Colt made that used that specific grip. Nothing else will interchange.
Due to the limited time the 2 inch Lawman was made, most grip companies never bothered to make after market grips to fit.
What you may have to do is have someone like Herrett's make you a set.
Herrett's is an old line maker who fits the grips to your hand if you send in a tracing of it.
I'd start off by contacting them about a set for your Lawman:
http://www.herrettstocks.com/