Windshield wiper refills for 64 Barracuda?

If there is only one refill number then based on what @Mopar Tim posted then they all were ANCO pushbutton.
The last production refills by ANCO was called 12 series. For 13" you're looking for a 12-13. Trico called those refills LP, so LP-13.
Or you have to use the clip in type of refill that is the same width as the blade's claw. I forget the Trico series number but it is still made as far as I know.