Yeah, Jim Cullers has a pretty good selection of goods there at Ft. Chambers. I've known him for years and stop in at least once or twice a year when I'm in town visiting the in-laws.
Conococheague Trading Co. is also on Black Gap Rd. between Scotland and Fayetteville. It's sometimes hard to catch him open there and he doesn't stock quite as much goods as Jim, but you can find some goodies in there too.