I remember that in Italy, early '60s, we used a straight 3:1 fuel (75% Methanol and 25% Castor). Only Speed Controline used 4:1 Fuel (80% Methanol and 20% Castor).
At that time we only used Castor Oil as lubricant. I think FOX still produces a mix with 5% Nitro and 28-29% Castor Oil, to be used on FOX 35 engines (and the like) in Control Line.
Ciao
Beppe