Ain't Garands great? Is there an import mark on the barrel? I've got 3 and am someday going to have Hook Boutin build one of them up to NM specs with a 7.62x51 barrel. From your post I don't think that is what you are wanting to do. Whatever you have done, remember that the JCG Match requires the weapon to be "stock." Not even a NM op rod which was a common rebuild addition.
"Service" and "Field" grade means nothing except maybe a reference point; these are CMP designations for the sale of their weapons. The wood may or may not be appropriate if you are looking to "restore" the rifle to "correct" condition which was all the rage for a while, and may still be. It can get very expensive looking for correctly marked parts (drawing numbers, cartouches) for a rifle. I've got an H&R that I would still like to bring back to correct status, but when I see a part that is right and then check the price I have to ask myself "why?" Most Garands have been through at least one rebuild. No big deal.
So after looking at your list of want-to-do's I have again ask why? You may want a walnut stock, but good luck on finding a nice one at anything like a reasonable price, then if you get an after market stock like a Boyd's you may run afoul of the JCG match rules. I'd go along with a rebarreling, but I believe the accuracy requirement for a Garand was 4 inches @100 yards. Finally, I really don't know what you mean bu rebuilding the action and rear sights? The parts are either the bolt either head-spaces or it doesn't, the small parts are either "in spec" or not, the rifle either functions as designed or it doesn't. If you are talking about a match trigger job or match sights, again you may run afoul of the JCG match rules.
Personal opinions about the people involved and marketing hype aside, the Fulton Armory web site used to be a great source of information.
Not much help but as you can tell I really like Garands.
Heck, get someone to rebarrel it for you and get it parked if you want it to look purdy, then shoot the heck out of it! That's what they're made for!