NOTE: UNIT NOT FOR SALE WITH MOTOR OR BELT KITS.) 
MR. CHRISTMAS  Piano Symphonique Grand Piano Music Box  ( APROX DATE CODE 1990'S) REPLACEMENT BELT KIT . OUR COMPANY HAS PUT TOGETHER A REPLACEMENT ROUND BELT REPAIR KIT. 
KIT INCLUDES 
: ONE  ROUND BELT 
APAPTER INFO: 3VDC @ 200MA (2.1MM X 5.5MM FEMALE  attached to rear leg.
To replace belt:
Remove legs first, then  loosen three middle screw on bottom, loosen screws to remove top black plate and remove , slide plastic insert with keys out . 
you can find belt on side under plastic sheild.