M1 Garand National Match Parts question

[ol' scratch]

Were NM gas locks ever produced? I just picked up an H & R Service grade rifle and it has an M on the gas lock. It is a low hump. It also has an original LMR barrel with a throat erosion of 2 and a muzzle of 1. Lots of fun at the CMP today. The stock is also original, but the rest is a mix of WWII and Post war Springfield. I did get a early war milled trigger guard with a lot number on it. I will post pics of the rifle when I clean it up. The stock has a few character marks, but has a very nice honey red hue.

Also, I know they used some LMR barrels for match rifles for the type 2 match rifles. Mine is marked with the following LMR D 6535448 2 55 A 41 and what appears to be a heart or a shield. Serial number is a 563xxxx.

 

[ol' scratch]

I found the answer on my own. For those who are curious, the 'M' was a type two gas lock. The 'M' indicates it was hardened for use with the M1 grenade lancher.