The 1969 and early 70's refills and the original assembly line were exactly the same. 3 ribs, patent numbers, and skeleton back.
The ones with the metal strip were later years or may even have been for a different arm type?
these were available from Trico as:just the rubber Refills = RF, or Complete blades = I think those were tagged LF?
I saved a 12 case of these for myself - last time someone managed to convince me to part with a pair - think they paid me $35.
When I went looking for that picture today and found the Dots pair for 63-65. I had to control myself and not buy them for $100.
those are just impossible to find for the Corvettes. and the ones on my 63 driver car are streaking a bit
my wife would not be happy if she found that I paid $100 for a set of wiper refills, especially when I don't like to drive the car in the rain. LOL