Look at #1, beneath the GHS is a ghost stamp outline underneath that "could" have been a CMP 'DAS" stamp that was sanded and sweated out to raise the grain for restamping. The ordnance wheel 'genie bottles' doesn't look right compared to known originals and too deep/perfect.
Pg #1 All Products
Pg #2 All Products
#2 - the silvery finish may denote a Letterkenny Army depot (LEAD) refurb.
#1 - Gas cylinders on M1 Garands were made from stainless steel due to corrosive primers, op rod tip was also stainless and silver soldered onto the end of the op rod. The stainless cylinders were then chemically blackened (The US used a number of methods to blacken gas cylinders through the service life of the M1 including paint, molten dichromate black coating). The Greeks used a heavy black paint "Greek Black" to refinish M1 Garands sent to them under the MAP program which is a different finish than the Brits "Suncorite" used on the SMLE/Enfield of WW I/II.