Can you find out who was the manufacturer of the gun and the serial number - or the serial number range?
This might give you a better idea of whether the gun has already been refinished once already (meaning the originality has already been affected)
Springfield Armory, Winchester, Harrington and Richardson - and Internatioal Harvester all made Garands. From everything I have read pretty much all Garands that were built during WW2 would have gone thru a rebuild process at some point along the line. A lot of the Garands built during the Korean War era never even saw combat - and are generally in much better shape than the WW2 era guns. I just recently got two Korean War era "Correct" grade Garands from CMP - they are both in excellent shape and the parkerizing (as far as I know all Garands were parkerized - not blued) - is in excellent shape.
The cheapest Garand listed on the CMP site at the moment are "Rack" grade Springfields for $445.00 - these would be pretty beat up and I bet the barrels would be getting close to shot out (no bullet showing when inserted into muzzle)
There is a buttload of information available on the internet on Garands - I would check out the CMP forums (
www.odcmp.com) and ask questions there if you are looking for some very good info - there are guys there who live eat and breath Garands.
For whatever it is worth (this is a generality) - there are very few WW2 era guns that are left in original condition - and the WW2 era ones are the real collectibles. You can get Korean War era Garands that are all original - but they are not as collectible as the WW2 era guns.