Found this on the CMP site - may be sticky material. One of the most comprehensive lists I have come across.
US manufacturer markings information (as of 9/4/1944)
http://www.odcmp.com/Sales/pdfs/Carbine_Parts_Marking_Information.pdf
MS
US manufacturer markings information (as of 9/4/1944)
http://www.odcmp.com/Sales/pdfs/Carbine_Parts_Marking_Information.pdf
MS
