Hewlett Packard 6439B DC power supply 0-60 V / 0-15 A - As Is for Parts

Hewlett Packard 6439B DC power supply 0-60 V / 0-15 A It has only a mV hum when loaded with 32 V / 3.2 A.

Seems to work OK but is erratic in both voltage and current (the potentiometers?)! Dangerously, it sometimes drifts up to a 70 V output!