Not able to identify these

I'm not sure what you have, unfortunately. There are dozens of different balances with these stamps. They're not product codes or anything, they just indicates the strength of the spring.

In order to figure out what Series this is, I need you to remove an undamaged version of this balance from the window and show me clear pictures of the top and bottom nylon fittings. I will also need to know the dimensions of these fittings.

Thank you! This balance appears to match our S395-26. This has a 19-005 top and 15-001 bottom nylon fitting, which appear to match your originals; as long as the dimensions of these fittings match then you should be good to go!

Since your old stamp is 25-4, you'll also want to select the 2540 option when prompted.

Awesome, thank you very much, George! We really appreciate the business. 

Please let me know if we can be of any further assistance.

That's great news! I'm glad to hear it. Thanks again for your order and feel free to reach out for any projects you may have in the future.