Thanks for posting, John. I recommend that you consider either our S385-30 or S380-30, depending on the size of your bottom shoe. Look them over and see what you think. As for the old balances not working properly, it may be because of the stamp. Your old 29 5 (our 2950) is meant for sashes weighing 28 through 32 pounds, which is too strong for a 24 pound sash. For that, I'd recommend our 2940 option (23 through 28 pounds). That may be better.