For valve based radar tech you could do worse than look to RN kit from the 50's and early 60's- look at County class destroyers and the fit on the Tiger and Blake. The latter also have advanced (for the time) valve computer based gun AA fits, at 6 and 3 inch calibre.
For an 'atom punk' power plant it's likely that a high output reactor would need a large heat dump to get the most efficient use of it's energy and manage potentially runaway feedback loops- a seawater based system is the usual approach on ships but a rapid venting of a secondary circuit is a useful backup, so some sort of emergency vent vale arrangement on the upper works that can purge some systems without blowing the entire EW fit over the side would be cool. suitably marked up with warnings too.
Missiles of this tech era tended to be pretty heavy at launch, and need a lot of TLC in storage and prep- valve guidance, cantankerous liquid fuel engines. There's a 50's Swedish destroyer in Gothenburg I visited (well worth it)
http://en.wikipedia.org/wiki/HMS_Sm%C3%A5land_(J19) that has a huge SSM prep space in it, with a sloped lift up to launch positions on the upperworks- very informative and full of lovely tech. The 50's UK Seaslug system also had a system of a long horizontal magazine toward the end of which missiles were prepped for flight. The upshot of this is that except for long range ballistic systems, vertical launch silos and box launchers are wholly inappropriate. Instead you need large magazines, armoured ideally, with ample spaces to prep complex machines for use, and then large doors and lift arrangements to manouvre these things on to heavy powerful trainable launchers. There is a good reason VLS came in when it did in western nations- until then you couldn't really trust a missile to behave itself after being stowed in a box at sea without care and attention, and even if you did, the beasts were way too unweildy to point themselves in the right direction soon enough after launch.