Good morning, Mr. Garlock,
I flew TH-55s when I went through the U.S. Army's Rotory Wing Qualification Course at Ft. Rucker, AL back in 1984 - 1985. I congratulate you on your purchase. It's a great helicopter and you will have a lot of fun flying it!
While my background is that of a warbird pilot and examiner, not as a maintainer, I think that the best strategy would be to certify the aircraft in the "Experimental - Exhibition" category. I believe that this would provide you the most flexibility and still permit you to do most (if not all) of the work yourself. Again, I am no expert on this matter - I just fly them and then hold the flashlight for the person who does fix it - but most of the warbirds that I have flown have been in the Experimental-Exhibition Category.
I do have some contacts that are operating warbird helicopters. Perhaps they can provide you more complete guidance. I'll give them a call and see if they would be receptive to talking to you about this subject. (Most are, I'm just trying to be polite.)
Go to my website, www.FinneganAviationServices.com and look under "contact us" for my information. Give me a call anytime!