Hello,
We'd be happy to help but, unfortunately, the stamp code does not identify the balance you have, only the strength of the springs. To get started, we would need to see photos of an intact balance removed from the window. Make sure to include both end fittings and the clip at the end of the pulley cord. Thank you!
Thanks for getting back to us. We've come across this top sash guide in the past but, unfortunately, we have not been able to find an exact match. With that being said, the 18-203 may be worth considering as a possible replacement. Note that the mounting hole will need to be drilled since it doesn't match the height of the original hole. Review the dimensions below and see what you think.
As for your channel balances, we can supply replacements but we'll need to see the connecting point between the pulley and spring to confirm if our stock balances would work or if it would need to be a custom order. Thank you!