Anderson double hung sash balancer help

Hi folks,
Hope you can help find this part for a rather old Andersen window. Here are the specs:

Stamped 11600-2 and D97 7#27 8 79 on the window side
Stamped 11600-3 on the casing side above patent numbers

Thanks!
P.S. I tried submitting a photo but the site kept having an error