You can also join hte
Garand Collectors Association for $25. They are able to provide your membership info to the CMP on-line.
The Rack Grade rifles are probably shootable, and they are fairly beat up. You receive the rifle in Cosmoline, so you'll be cleaning it for a while. I also understand the stock is Cosmo'd, too.
I will be buying at least one Rack Grade rifle and having it worked on by
Dean's Gun Restorations. Having them do a bunch of work on a higher grade CMP Garand is probably wasted money for the higher grade.
Do not have a Correct Grade or Collector Grade reworked. Leave them as-is. They are worth more as collector guns that way. As soon as you have a collectable Garand reworked it loses much, if not most, of its value.
Unless it is a collector, CMP Garands have all been reworked at least once. This means they are a complete mix of actions, bolts, trigger groups, barrels, and stocks. A Sprinfield Armory, WW-II era action might have a bolt from the late 50's, a Winchester trigger group, and some aftermarket stock. They are probably refinished, at least once, and likely done at the country we loaned them to. Most Garands currently available from the DCM are returns from Greece and Denmark.