On my recent trip to London I also visited HMS Belfast. I've seen her a few times before from the outside and I remember extensive coverage of this floating museum in one of our popular science magazines several years ago, but until now I never found the time to actually go on board.
The ship is well worth a visit, even if you're not particularly interested in military technology. Although in terms of electrical engineering there's not much to see. Most of the original electronics equipment is gone, supposedly because it was still secret when the ship was decommissioned and opened to public. You can see some racks with radios from afar (with added random sparks, for theatrical effect) and a workplace for a group of veteran HAM operators that still answer the original ship call sign. Original CRT radar displays have been replaced with a surprisingly authentic-looking mechanical simulations using rotating semi-transparent screens.
The engine rooms however more than make up for that. If you're into steam turbines, big brass gages, huge transmissions and other such things, of course. Compared to rooms housing electrical equipment where you have to stay behind fences and closed doors, here you can actually look at the control panels in detail. It's interesting to pause in the cramped spaces between various conduits and try to figure out what is the purpose of this or that instrument.
Above, by the way, is a mechanical analogue computer for calculating ballistic trajectories called Admiralty Fire Control Table.
One other interesting thing I noticed during my stroll around the ship was a distinct lack of chairs for the crew. Except for the rooms where the crew slept and ate, almost all work positions seemed to require standing, as also demonstrated by occasional mannequins in the exhibition. That rang a bell since it's a standing joke about Star Trek that it features futuristic space ships that lack chairs and seat belts. I wonder what the rationale behind their absence was in the case of this quite real battleship. After reading recollections of various battles that were on display in the museum I had the impression that being thrown into the nearest bulkhead was a quite real possibility.