Nice score! Probably running 250 I6, take pic of passenger side engine and also if motor mounts are straight across from each other its 250. Other possible is 292. If your wanting new repro parts then check with some of the board vendors, otherwise hang out here and watch for all the parts posts.
Check this out for seat covers
http://www.ricksupholstery.com/ they are awesome. Just call and they can do whatever you want for way cheap. They do custom for price of generics basically. Otherwise just make sure tires are good, brakes, steering linkages, just main stuff and drive it!
Here's some good sites for ya
http://www.stovebolt.com/
http://www.inliners.org/
Do lots of searches here and go to the faq section and browse also. There are a lot of good guys here that help us.