beaker: Whilst plaing with this I had a thought. These are often said to have been for fishermen because of the shortwave frequencies available, but surely this would have been a bit fancy for a fishing boat. I would have thought it would fit in a lot better in a luxury yacht, especially with the white colourscheme.
I believe the story was that these were rather for fishermen's wives who could listen to the traffic, and perhaps have a clue when to put the kettle on In the boat, you would've wanted a radio that transmits as well.
Lovely to see one of these being taken care of! The power supply seems indeed very much like something that could've been constructed in the 60s. Hard to say from the pictures of course, but to me it seems like it was built by somebody who knew what he was doing - just ensure that the live parts and connections are well insulated and spaced from the low voltage components, and I would expect it to be quite safe to use.