~25 year old wooden Andersen window balance

Question

I can clearly make out 11600-17 on the associated photo. A search through your past posting indicate that's not really helpful, though. There is what appears to be a "576" stamped on the opposite side, but that doesn't appear to match the codes on your site. So, I was hoping you could either

1) identify the part by seeing something I'm missing or

2) let me know where else to look for stamps/markings.

I didn't want to remove the part yet because it is holding up the upper half of a double hung window.

User submitted photo of their window balance.

Tom · Accepted Answer

Hello! The key stamp here is on the bottom. I've provided a picture here of it blown up.

I can just make our "9#27," which is exactly what we need. If you can confirm, I'd recommend our 24-939 Andersen sash balance.