Many thanks for posting. I have cross-referenced the data you have provided with our records and came up with the following:
Sash #1 should actually have 26-1/4"long balances, not 27-1/4". Please recheck your measurements. If they are in fact 26-1/4", then for Sash #1 weighing 16 pounds, the balances stamped 3060 can be replaced with the S745-26, with a stamp of 25.25-3.
For Sash #2 weighing 20 pounds, the balances stamped 3654 and 23-1/4" long can be replaced with the S745-23, stamped 22.25-4.
For Sash #3 weighing 16 pounds, the balances stamped 3060 and 26-1/4" long can be replaced with the S745-26, stamped 25.25-3.
Finally, for Sash #4 weighing 18 pounds and with balances stamped 3660 and 26-1/4" long, go with the S745-26, please double-check the sash weight. If it is indeed 18 pounds, then you want to again go with the stamp stamp 25.5-3, which designates a balance that can support a sash in the weight range of 13 through 19 pounds--if it is outside that range, let me know.
Let me know if that all makes sense, or if you have further questions.
