Technics SE9600 please identify these parts

Hi guys. A couple of days ago I received a Technics SE-9600 power amp. Someone applied new thermal paste to the power transistors on the heatsinks (which is not a bad idea) and mixed up the positions of each transistor (very bad idea...).
Now I have to resurrect the amp.
I'm having trouble finding a replacement for the following part:
D510: RVD10D1 the manual only says "meter detector"...
Could anyone tell what type of diode this is? And what replacement I can use?
I'm pretty sure there are more hard to find parts in this amp...