How rare is this and what's it worth?

I'd say $3800.00 would be a fair price. Humor the guy and do the interview. If he sounds like he wants you to keep it stock then convince him you will. Once the title is in your hands you can do with it as you please. I always try and follow a lead on a car I am excited about. A lead can always lead to other great finds. When I was searching for a replacement Barracuda body I met a guy who had a rough notchback in his garage. I passed on the car, but I did take home his super rare A-body 18 spline 4-speed for $250.00! So, never discount what may be waiting for you out there. BTW my search also ended in me discovering my 1969 'Cuda factory big block 4-speed car fifty miles from my home. It was hiding in the parts section under Mopar parts for sale on Craigslist in Houston. Final tally was 3250.00 for car and 4-speed. Went to an old junkyard outside of Houston filled with random weird old cars. C-bodies and El Caminos, wagons and stuff. Talked to the owner and he had two 8 3/4 third members stashed on the floor of an old Chrysler. One 742 case with unknown gears and the other a 741 case with 741 case with my dream gears 3:91's! $60.00 later and I was taking them home. Might sound like I am bragging, but I am actually saying it really pays to be friendly and talk to people. It's not always about money, but sometimes just meeting new people and making a friend. I earn $12.00 an hour and I own my dream Moparbecause I took the time to talk to these people.