A question: in the "early" regulators/rectifiers there are 2 round, metal electronic components pushed into the back of the metal box.
On this picture you can see them on the very rhs of the metal box.
![Image](https://motomoriniclub.nl/spann1.jpg)
This way they get sufficient cooling. In the past I found out these 2 components are PS620 (0.5 Amp). Searching the internet I did not find any reference. Does anybody know if these components are still available? What are they? Transistors, thyristors, something else? If no longer available, what would be a similar, replacement item?