To me, nothing in the pictures jumps out as being anything other than original.
I'm certainly not a Mustang 'expert', but I've owned a 1975(ish?) Mustang since 1982(1?) that there's no reason for me to believe has been modified in any way. Most of the parts and lettering look identical, with the exception mine has an additional string tree and all-metal tuning keys. There are a few good internet sources you can Google, of course, for specifics on that year, but most of them acknowledge that there doesn't seem to be a definitive 'bible' on what Fender made and when.
Sorry for the late post, just saw this and figured a response might help someone somewhere.
