I have no knowledge of what the original sandwich was like. We didn't have Bob's, Shoney's, or any other Ellias Bro's franchise down here featuring their sandwiches and burgers. My mate's been jonesing for one like Shoney's made them when they were a franchisee. There's many conflicting recipes and reminisces of what the sandwich was on the web. The only thing for certain was ham, Swiss cheese, thin sliced tomatoes, shredded lettuce on what appears to be a sesame seeded bun. While it seems pretty generic, everything diverges from there.
The sauce I've read varies from a Thousand Island to a simple sweet mayo/relish tartar sauce, to a complex Dijon/tartar-like sauce with Tabasco.
Some versions have a sweet ham product, others a bolo ham. Was the ham pre-grilled or not?
Was the roll a baked sesame seeded Greek roll, soft roll like a packaged Pepperidge Farm or Cobblestone mill type, or something else?
Some versions claim the sandwich was pressed, others baked until the cheese melted.
Maybe there was variation between the franchises. I'd like to find someone's recollection of what the Shoney's version served was like in the early 70's.
2nd Edit: correcting corrections