I did mod a LM Sheath (From a PST, I guess) to fit my MP 400 a while ago.
Original vs. LM sheath
Sorry, pic is blurry, but you get the idea...
Shoulders of sheath trimmed to clear the Locktabs
Punched a hole from the top, I centered the punch with a piece of pipe and four bolts.
Edit: The Sheath, including it´s inhabitant, is available for sale trade....
Eyelet in the bottom to fit the Needlenose plier head.
and while at it, i replaced the busted and loose button, too