Tough to tell from the pictures. I'd sure go over it with a find tooth comb. Just because he claims it's rust free doesn't make it so. Problems areas on 69's are the rear quarters (water collects in the corners of the rear window and tends to eat through the channel, down into the trunk, and take out the areas around the wheel house and lower edges), the bottom edges of the front fenders behind the wheels (there's an inner fender brace in that spot that tends to trap moisture at the bottom), and the on the cowl along the bottom of the windshield channel. Another problem area can be the rocker panels.
Without the original engine it'll never be a 6-figure "Barrett Jackson special", but if it's really a solid and almost paint-ready car and you get a date code correct RA III with it (along with all the associated RA system parts, and other things that appear to missing in the photos such as grilles, window trim mouldings, etc.) then it could be a worthwhile deal. *IF* that's the case, to take it from where it is to being near show-quality, you're probably looking at another $25k-$30k depending on how much of the work you can do yourself and how much is missing (body, paint, and drive train being the big ticket items). I'm not 100% up to date on the market, but I'm guessing a non-"numbers" but otherwise pristine and date-correct 69 Judge RAIII 4-speed would probably bring $60k-$80k on a good day.