And I would say to your explanation, why is the font size of the “M” in the P.M time of the “messiah’s” birth so obiously smaller than the rest of the type? I was alive then and I knew about computers - big ass things. I’d never heard of font size, computers that were used for everyday office keeping duties, etc. The "M" is the same size font as the pre-printed elements of the form. Considering that both "A.M." and "P.M." end with "M", it looks like the form was constructed so whoever was entering data would only have to type "A." or "P."