Two small sugestions.
1) solve the Barbette issue by not having barbettes separate, instead have gun and barbette as a single unit. så you select gunzize then number in turret, then "normal/superfiering/doublesupperfiering. this way you can handle both visual and weight calculations better.
2) for uss that dont spend every waking hour reading upp about historical ships. could you place some mouse over popupp with historical info to compliment the raw data for different parts (especially hulls)
Stuff like
years it was used,
Ship types you can build from this (like was used in shipps x,y,z)
avantages/differences from earlier types of the same component.