OK. That pair is working in a 0-30v 4/5A regulated power supply. I forgot to post it, sorry.
I searched and 2SD381 datasheet and I find two options, the first is a Silicon NPN Power Transistors TO-220C package, and the second, a Audio Frequency Power Amplifier, Low Speed Switching.
These pair of transistors work in addition to a LM723CH
That helps, some. Unfortunately, the 723 can be used with either NPN or PNP external pass transistors. Schematic? Photo of both sides of the circuit board?