I visited the Camp Perry, Ohio store last year. They are great folks to deal with and extremely helpful. I've since made a couple of calls to obtain information and have found the same courteous assistance. All the information you need is on their website including order forms and the qualifications you need to make a purchase. The web site also provides up to date inventory information and detailed descriptions of the various grades of the firearms they sell. Right off hand I don't know the official URL to their site, but if you Googled CMP.com you should be able to find the link to the actual site.
If you are anywhere within driving distance, I would suggest a visit. Its a great place to be and the folks there will dazzle you with their knowledge of U.S. Military firearms. They also have throat erosion gauges that you can borrow. Should you decide to visit, have all your paperwork in order before you get there.
EVOC ONE