You can go here: http://forums.thecmp.org/forumdisplay.php?f=7
to find folks that have all the answers you need. Please have serial #s and any numbers you can find on the rifle. The good folks on that forum are true M1 Garand experts and can fill you in on whatever information / history / provenance that you wish to learn.
Not only that but you can also buy another Garand from these same good folks.
CMP is good people Kimio, they have the information and the guns.