Ryan McAvoy said:
I don't wanna see new republic Star Destroyers. They're too associated with evil to suddenly be good. Imagine a shot of Luke standing on the bridge of one, he'd look like a Sith lord simply by association.
That's a captured Japanese Zero with American markings.
http://commons.wikimedia.org/wiki/File:Akutan_Zero_in_San_Diego.jpg
In any case, the Rebel Fleet probably took a severe pounding after Endor. Would they pass up useable ships that could be repaired and take on the Imperial remnants on an equal footing? If patching up a derelict star destroyer is good enough for a space pirate with a vision...