Andersen sash replacement balance and hardware

Thanks for posting. In theory an Andersen balance box stamped L9-1327 on the left-hand side would have a specific replacement for the righthand side, our 24-R13-927. That doesn't match the stamp on your old balance box, however, so to be extra careful I'm going to run this discussion by one of my senior colleagues who will know for certain. We'll get back to you as soon as we can with more information. Thanks for bearing with us.

Perhaps I can be of assistance. Back when I repaired some Narrowline screens, we used the 59-250 foam spline. Look it over and see if this matches what you need. 

As for the sash balance, I can't find any with a stamp of R26-939, but Bob is right that the opposite-handed box for the 24-L9-1327 is the 24-R13-927. To make sure this will work for you though, can you give me the width and height of the visible glass for both the bottom and top sash? Thank you.

Thank you for your response. We can now confirm that the balances will be the 24-L9-1327 and the 24-R13-927. Remember, do not mix up the balances when installing. Note that Andersen considers the left and right by looking into the house from the outside. Let me know if you have further inquiries.