When I got to the wipers on my 1969 I found a seller in MI that had NOS period arms and blades (possibly production parts).
BEFORE you buy reproduction parts - I'd look into NOS ,anco , wiper arms on Ebay, research and compare.
Mark
P.S. Sorry I don't have info/link - but this is a great area where a bit of research might produce a 300% better option. (They weren't that expensive either under $100 for the arms and blades)