Amesbury block and tackle replacement

I need to replace some block and tackle for my double-hung windows. There are 2 sizes - 4 bigger ones (dark background pictures), and 9 smaller ones (wood background pictures). I measured and picked out some part numbers but would like confirmation before I order them. They look mostly like the Swisco 775 series with a 1.25" shoe.

My guesses (count - length rating (weight of window)):
18 - 24" B (15.5lb)
18 - 26" B (16.5lb)
8 - 28" C (17lb)
8 - 30" C (19lb)

thanks for taking a look!

By the way, the windows have very little markings on them. I suspect they are Amesbury after looking up the patent number.