Hitachi HA-M44 IC replacement to STK
In reply to Chris that requires me this technical information (the original post disappear).
At the following Link you can find the improvement sheets you need:
After the Ic replacement you can add the needed parts behind the PCB pattern directly on the IC's pins (care just the insulation of these parts with other components).
I dont know if you'll be able to find out the required STK IC. In affirmative case you can proceed with the improvement.