But yes, you are right, the ES-330 was the Gibson equivalent, being fully hollow. The Sheraton (and Riviera) on the other hand had the center block. Well, I meant the Casino, rather than being a design of the Epiphone company that pre-dated Epiphone's purchase by Gibson, was made from parts of the Gibson ES-335 (the 335 being the first guitar to have that shape body), and it had its top, back, and sides (but not its center block). In 1984, Gibson moved from Kalamazoo to Nashville, TN. In 1970, Epiphone production was moved from the United States to Japan, and later South Korea, Indonesia, and China, and even Czechoslovakia. The Casino, for instance, shared the top, back, and rims of the Gibson ES-335, and had Gibson P-90 pick ups The Sheraton was a near copy of the ES-335, but with some cosmetic differences. Later, Gibson would introduce some solid bodied Epiphones of unique design, like the Crestwood. At first, these were Gibson-derived instruments (basically rebadged Gibsons or new models based closely on existing Gibson designs, as opposed to the models Epiphone had been making in New York and Philadelphia when they were located there). Gibson bought the Epiphone brand name and some of their manufacturing tooling and parts inventory in 1957, and began making Epiphone branded guitars shortly after in the Gibson factory on Parsons street, and later an adjacent building. They were made in Kalamazoo, Michigan, by Gibson.
