I would love to see a manufacturer come out with a 2 in 1 kit that you could build either / or of a certain subject.

I was thinking of the Nevada / Oklahoma, Tennessee / California, Maryland / West Virginia.

It would be nice to be able to select which ship from the same class you would like or even buy 2 kits to represent 2 different ships. Would it be hard to have a basic class and ship specific spru's in the same box?

Interesting question, Dragon (and others) do it for armor all the time. Aircraft models, you also see it... either different markings or versions (day vs night fighter). The newer 1:700 Dragon premium kits give you the choice of versions in many cases, you can buy couple of the same kit and have 2 different ships. it is not even a question of economics, since we still have to buy TWO boxes to make the 2 ships!

Some kits are that way but very few. I remember that when I put together my HMS Exeter (type 42 class destroyer) that I had the option of making any one of the four of the type 42 batch II destroyers. The instructions did list the minor changes needed to differentiate the model between the four ships. The kit was the 1/700 HMS Exeter from Dragon.

It would be a great concept, the 2 ship classes of Tenn/Calif and Mary/WestVa are pretty similar in appearance all being cage mast at Pearl. But they had different main gun arrangements and probably a host of other differences. Heck, most of the ships in the same class were different from each other and require modifications. Tanks are easier becasue 100's of each type were built. A lot of times it is easy for a company to do the multiple varieties because they can take a sprue from one kit and throw it in the box. Like say with Dragon's panzer III. I bought one kit and there were sprues from 5 other kits in the box. Ships probably aren't cost effective that way.

You'd be surprised, I have built a few modern ships that had a spruce or two in common with each other. I think it was a Spruance class and a Type 42 class that had a sprue in common. The two ships had no weaponry in common but the sprue had weapons parts for both and more on it. One of the guns looked like it belonged to a Russian destroyer but I never researched to find out for sure. I have yet to come across that in WWII era ship or a sub from any era but I have seen it happen a few times on modern surface vessels.