Don't believe typewriters could produce supercripts in 1972? Well, the fact is, Bush's own WH released military records show such a supercript on his Chronological Listing of Service. You can see it here.
It's a PDF file. Scroll to page 3. Then look at the 4Sep68 entry on the second line. Zoom 200% and look at where it says "111th" Fighter Interceptor Squadron." There's your superscript in the "111th."
Or, I've clipped the relevant portion and blown it up for you here.
