Steam Engine Pulley for 30 Note Music Box
Free     Myminifactory     SleeplessEngineer

Steam Engine Pulley for 30 Note Music Box

You can see this pulley on my youtube channel Fits right onto the music box without any modification  Just add two M25 screws to secure the pulley  Might also work for 15 and 20 ...

similar models —

Steam Engine Pulley for 30 Note Music Box alternatives
Beam Engine
WarnerPrinting