Diner Stationery - Really? (Back to the Future)

Good grief, this film is almost a quarter century old. Anyway, before returning to 1985, Marty writes the famous letter warning Doc Brown about the Libyans. Marty’s writing it in the diner, apparently using a restaurant letterhead. Was it ever common in the 50s or any other time for lunch counter - malt shop sort of places to provide writing paper?I’ve seen such in motels and could imagine maybe free postcards at a tourist destination restaurant. But an ordinary diner in Hill Valley? Isn’t this weird?

Businesses, even small ones, used to write a lot more letters, say for orders and payments and such.