Item 22. After seeing another document, with the address, I believe it is a pre-printed letterhead. I do not believe a printshop would use the raised "th" in a letterhead.
The centered heading in the 4 may document looks to be the same typeface, sizing, and layout as the rest of the letter. Pre-printed forms in 1972 were usually done on physical linotype machines, and would certianly have been different. There were very expensive offset printers in those days, but this looks like one of those things like, "well, it COULD have been done by X".
Well, it likely wasn't, and you get a couple dozen "likely wasn't" and you're into PROOF of FORGERY territory.