Over and over I see a common thread of those wanting to convert an available plastic model to a specific ship.
If you google nmah ship plans you will get to a Smithsonian site that has the plans for all sort of ships. They are in three catagories: Water Craft, Warships mid 18th century to 1900, and the Marad Collection of Ship Plans.
The Marad collection contains the plans for 55 ship types built from 1939 to 1970 including the victory, liberty, C-3 and C-4 ships in their various cargo and military configurations. (Sorry no C-3 conversions to aircraft carriers). Also the T-2 and T-3 tankers. These plans are what were used to build the actual ships and are not reconfigured with model makers in mind. Generally there are around 20 sheets per ship and big - like 3 feet by 8 feet. There also are 50 sheets of drawings for the SS United States.
The mailing address is: Ship Plans, Smithsonian Institution, Maritime Collections, NMAH 5004/ MRC 628, P.O. Box 37012, Washington, DC 20013-7012, USA
There is a comprehensive index for the Marad Collection - some 70 pages. I don't know what the current price is.