[dataway]

I'd say, going from the perfectly consistent finish on the cast metal that it wasn't restamped. Usually a restamp requires grinding off the old numbers which leaves obvious signs on the finish of the casting. My guess is that part number had numerous digits that remained unchanged throughout a range of applications and the stamping machine only changed the applicable digits and used a different font when it did so.

Meaning, if a part used the form XXXXYXXYY and the X's were the same for a run of thousands of starters and only the Y's changed, they would probably stamp all the X's first and then stamp the Y's later depending on application.