i would assume that the war didn't just complelely end after the Death Star was destroyed, and that it also probably went on a good deal of other planets too. it would make sense that there would be some wreckage of the war to found pretty much everywhere
yeah it didn't end with the emperor's first death, at least in the eu/legends
Also why is there a star destroyed on tatooine? wasn't that final stuff on endor?
yes the final battle of the original trilogy was above/on endor
doesn't mean star destroyers can't be found anywhere else before and after