1986 built house window balancer

Hello, thank you for posting,

At first sight, your balance resembles the Series 770 channel balance. To move forward, can you provide the length and the number/letter stamped into the metal? Does this balance install with a screw at the top?

Unfortunately we do not carry this pivot shoe. Can you provide the width and thickness of the original shoe as well as a picture of the pivot bar on the sash that engages with it? Thank you!