This is an old thread - but I recently acquired a model 65-5 4inch.
I called a friend at the S&W PC and he had a 3inch mod65 lady smith barrel.
I sent him my gun and said have at it.
Installed the 3inch barrel
Installed a trigger stop screw
Chamfered the cylinder holes and went thru the entire gun.
He wanted to DAO the revolver- bobbing the hammer but
I said no. I have a PC13'so I'll wait.

Got it yesterday. Beautiful.