1965 Factory Air Pulleys and Belts

The pictures in this document helped me a lot.
http://www.jholst.net/65-parts-manual/air-conditioning.pdf?

"Model 954" was stamped in yellow paint on my heater box and on the underdash vents. The pictures for Model 954 on pages 24-6 and 24-7 match my car very well. There is no "Roller" in these pictures, only an Idler which I have.

There is a Roller in something called the "Model K" on page 24-11. Model K is not what I have. Perhaps Model K is the dealer installed AC?

I'm also still a tiny bit curious about the mystery metal in my third photograph. My car did not originally come with Power Steering. The previous owner told me that they added it so his mom could continue driving it as she got older. Perhaps it came off a car with dealer air?