Anlin Window Double Coil Balance

I need a double coil balance replacement for an Anlin window. The only stamp I can see on the assembly is either a 9 or a 6 on the shoe.

I'll attach some photos. Thanks for any information!

PS One of the coils broke, so I suppose I could just replace that part. I am thinking that it would be best to replace both coil balances on the window, though. Again, thanks for any feedback and part information.

Frank

A Handy Old Geezer

Finally able to find the stamps on the springs: one 5lb spring paired with one 4lb spring. The sash weighs just under 19 pounds. The correct replacement part appears to be either the S140-09 or the S140-10. (tilt in sash)

Is there an advantage of using a double coil balance vs the single coil balance? The lightest weight S140 double coil balance you have listed is the S140-12. I'm guessing that is too much spring for my 19lb sash. Do you have any double coil balance for a 19lb sash? I cannot find a replacement spring with the correct attachment point for my existing shoe.

Thanks again for any feedback/information.

Sorry. The above comment should have said the S140-11 appears to be the lightest weight double coil in the s140 series.