I have had good luck with surveyors Fred Wise and David Manning. Manning will climb the
mast to do a cursory rig
inspection. For a full rig
inspection I'd highly recommend Walden Rigging of North East, MD if the boat is lying in the upper bay (they generally won't travel south of Baltimore/Rock Hall) and Dave of Bosun Yacht Services of
Annapolis.
I just completed a full re-rig of my boat and formed some negative or lukewarm impressions of some other rigging outfits while I was in the process of getting estimates. I'd be happy to discuss more via PM.
There are probably not many riggers who will do x-ray inspections. I'd also be very surprised if the seller would even allow you to pull the plates pre-sale as it's invasive and poses a risk of rig failure or creating
leaks if not done properly. For the rig inspection you'll probably spend $300 and for the pulling of the chainplates that could easily get into the $1-2K neighborhood. You might be better off to just assume everything needs replacement given its age, make a commensurate offer on the boat, and save your bucks for the re-rig
project.