The only Rifle powder listed by Sharpe, (that's still found today) is 4227 & 4759.
The 32-20 isnt a round that can use normal rifle powders however there are lots of loads listed for Unique and 2400.
Maybe talking to some Cowboy Action Shooters will get you closer to what you're looking for.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071