The first photos of the car
The first photos of the car show wheel discs from a 1957 Continental Mark II. All photos of the car in service show wheel discs from a 1957 Lincoln. It never had the wheel discs standard on 1961-63 Lincoln Continentals. Does anyone know why?
Modern repros of the car can be spotted by their different doors. The original had a 12-inch extension between the doors, and a rear door at least 4-inches longer than stock (plus a roughly 15-inch extended rear fender). The Repro(s) have stock front and rear doors, but a much longer extension between the doors.
Also I have noticed that, on the day of the assassination, the right rear door was never fully closed. Governor Connally would have entered after the president because he was riding in the jump seat, and apparently didn't pull the door hard enough to fully latch. The Secret Service should have caught that.