HAVE A KENWOOD 701A?

I AM A LICENSED REPAIRER BUT DON'T SEEM TO BE ABLE TO GET HOLD OF GEARBOX EITHER EXCHANGE OR SERVICE PARTS.

CAN YOU POINT OUT WHERE TO GO, AS WHAT TO DO IS NOT A PROBLEM PULLING THE EXISTING BOX APART WITHOUT INSTRUCTION COULD WELL BE DETRIMENTAL TO IT'S FUTURE USE THOUGH THANKS FROM MIKE QLD AUSTRALIA