Milestone Single Hung Series 1000 Balances

I see a stamp "Unique 28-C-30". The balance length (just the metal) is 29". The depth of the bottom fitting looks to be just under 1". I was not around to see the original installation or the maintenance, but I noticed last night that one of the balances had already had the spring and pullies removed. So I need for both sides. From your website, it appears that S380 is what I need. I don't have any scales but estimate the sash weight to be 30lbs.

I rechecked the sash weight, this time with scales. It is a hair under 20 lbs. Now I need 14 of these replacement balances. All the same style (S380 I think). Two of them I already mentioned are for sash weight 20lbs. The other 12 are just under 10 lbs.