Windshield wiper refills for 64 Barracuda?

I've been looking all over. I can't manage to find a wiper refill. Everybody wants to sell you the blades, but no refills. My blades are fine and don't need to toss them in the trash to spend money for something I don't need. I checked the service manual and can't find a part number there either. I may have missed it. All I know is they are 13" long, at least the ones that came on the car. I presume they are the correct size. Anybody got a lead on refills?