The easiest way I would suppose would be for some older soldiers here to compare there paperwork from the period and see if the type matches, may not be a perfect way but it is a way.
I decided to take your suggestion and looked back at John Kerry's DD214s, also from 1972.
Not only were multiple machines used, but proportional fonts as well.
Lines 1-10 are in standard evenly spaced fonts
Lines 11 and 12 are in proportional fonts.
The form then goes back to even fonts for a while, and then the bottom section is all in proportional fonts again.
Maybe I'm off base here, but something is wrong with the use of this type of font on Kerry's DD214s from 1972.
And the OFFICAL DOCUMENTS watermark is such a nice touch...