I had a cunning plan to do a Soviet SSBN in 28mm for a demo game but it got shelved. The hull would have ben in modular sections consisting of the compartments of the sub, from the nuclear reactor to control room to accomodation room to missile room to forward torpedo room. Each would be a basic rectangular box with the curved flanks of the hull made from sections of carved and sanded balsa attached on either side. The whole thing would sit on a sea /arctic base with lots of floating ice all around.
There would be a lift of rectangular lid for each section made up to look like the top of the hull, complete with missile launch hatches etc. The different rooms would be kitted out with Copplestone consoles, furniture etc plus ranks of missiles from deoderant lids. The conning tower would be a seperate section that would sit on top of the hull.
The scenario revolved around a Hunt for Red October / Ice Station Zebra type set up using Eureka special forces frogmen and Copplestone neo-sovs as the baddies.
I got as far as drawing up some semi-scale plans but then got sidelined off...
I did find some cool sub art on the web though like this:
http://www.dia.mil/history/art/images/sub_ship.jpg