I found this:
The MV Aquarama was a Liberty ship, built as USS Marine Star in 1945 in Chester, Pa., as a U.S. troop carrier, but it made just one trip across the Atlantic before the war ended. USS Marine Star was converted into a cruise-ferry ship that took passengers between Detroit and Cleveland in the late 1950s and early 1960s. A reproduction picture is now on e-bay
But reading further found this:
She was neither a Liberty ship, nor a motor vessel. She was built at Chester PA by the Sun SB&DDCo, hull no. 357, as a C4-S-B5 (a combined troop and cargo transport), one of five built late in the war and of twenty C-4s built by Sun. Liberty ships were designated EC-2 by the USMC, were significantly smaller freighters and powered by triple-expansion steam engines. As Aquarama, and now as Marine Star, she retained her original and massive twin GE steam turbines (9900 shp). The presnt McKee Sons and Joseph H. Thompson are converted C4-S-B2s and Sun SB&DDCo products, which were combined troop transports and hospital ships, the former Marine Angel and Marine Robin respectively. And, because of those thirsty turbines, both are barges today.
As for those different hulls:
This is the Marine Robin:
http://www.boatnerd.com/pictures/fleet/thompson.htm
The only other info I could find is this site here:
That’s all I got.