Thank you for posting, John. This balance looks a lot like our Series 770 channel balance. Can you confirm the length of the metal channel though? With that stamp, it should be 27".
If it is, then we're looking at two different options for the S770-27. The first option should be 27E, for the 28.8 pound window. Two S770-27 balances with the 27E option can support a window sash weight of 26 through 30 pounds.
The second S770-27 will have to be custom made, as we do not have a standard option that can support 41.8 pounds. I'll go ahead and email you a purchase link and price quote for your review. This balance has a special 27H option, which can support 38 through 42 pounds.
Review this information and let me know what you think. If your balances are, in fact, 28" long, let me know and we can try to figure out what you have from there.
Ah, I see. It's better to go with the length of the channel then, yes. With that in mind, I think you should instead look at our S770-28 with the 28E option for the first balance, and then I will send you a revised link for a 28" long Series 770 balance with a 28H stamp. 28H can carry 40 through 43 pounds.
