One of the recent reference books has a rendering of the Y-wing with its fuselage and nacelle cowling intact. Kind of neat. But the rebel materiel was never "scraps" ... Tagge (or was it Motti?) considered the Rebel Alliance "well-equipped" and a threat to the Imperial Starfleet. They did fight their way out of the ambush at Endor. New Republic official historians probably work hard to maintain the mystique of the Rebellion -- that the Galactic Civil War was a contest between unstoppable might and a small band of poorly-armed but courageous heroes. But the fact is they had a lot of support. So much so that the loss of an entire world barely fazed them. (That we know of, anyway.)