VINTAGE places DC/suburban MD/N VA

Just got back from a long weekend in central PA. Appreciated the vintage places still left in towns - architecture, stores, dining, drive-in movies, even roadside ice cream stands.

Can everyone weigh in with their favorite VINTAGE places around here? I hope to discover some new ones. Yes I know the food will not be cutting edge but it will be comforting, with the decor harkening back to yesteryear.

I already know about or have dined at Ben's Chili Bowl, Tastee Diner, Florida Ave. Grill, original Crisfields, Frank's Diner in Jessup, the original Ledo's, Eastern Market Lunch, Jimmy T's on Capitol Hill, Waffle House downtown, Harrington Hotel's cafeteria, Bob & Edith's, Frozen Dairy Bar (VA), Barbara Fritchie's Candystick in Frederick, Tastee 29 Diner, Jimmie Cone in Damascus, Thelma's Ice Cream (VA).
Any other vintage places I'm missing that you all are fond of?

Many thanks!

P.S. Bumpers, trying to build a (digital) drive-in theatre in Eldersburg, MD, is appealing the zoning board's decision (NIMBY's are fighting Bumpers). However, Bumpers has won a spot over in Taneytown (nr Thurmont) & have broken ground there. Drive-in hopefully will be open next May...