The Yamato as seen in SFC2 may not technically be a kitbash, but it's (IMO, anyway) a kitbash at heart. If you took a Connie refit saucer, 2 Connie refit secondary hulls, 4 Connie nacelles, 2 Miranda rollbars, and a few new parts (mostly the oversized "shields" connecting the upper and lower nacelles), you would have essentially the same ship.
Now, the original KA version may be different; I don't know, never played the game...