IIRC the original wiper blade is a "Wrist" type. It was very common years ago. I see them called "Bayonnet" sometimes today. They are not "Bayonnet" type.
11" blades are available:
https://www.amazon.com/Wiper-Set-33-.../dp/B071KVXV8H
I'm trying to find 12" blades as the 11" really don't cover as much of the glass as I'd like.
This one might work for 12"
https://www.ebay.com/p/Windshield-Wi...20-12/79247216
It looks like the blades in the picture are "Hook and Saddle" which are not original. With this type of arm the blades will "flop over" when the wiper arm changes direction.
Anco's site might help as well.
http://www.ancowipers.com/find-my-pa...tWindshield=No