I would add a couple things being into early Plymouth's since a young Man with my Dad, a lot of Parts do Interchange with other Chrysler cars certain models and Years, you can still get most engine things once you find that guy who has 5 blocks and three complete motors and you become good friends, that being said with time you can find most everything.The ad says it's been For Sale for 21 weeks I would say if you like it and want it start out after you go down and look at it with a offer of around 4800-5500 worst he can say is No and you go get a Nice Dinner and go home.
Cheers and Good Luck