The '55 and '56 Victoria hardtops are completely different. The '55 side glass is higher, and the quarter window is also much longer on the '56 and lowers into the quarter in a completely different fashion than the '55. For the windshield you could use a '55 Crown or a '56 Crown, Convertible, or Victoria; you would also need the vent windows from the same car unless you plan to delete them entirely. If you were willing to stick with the '55 quarter window shape and lowering method, you could chop them, but you'd have to reshape the stainless channel around the top of the window. Actually, if you're going to do a Carson top, why not just start with a convertible?