USS Buchanan, destroyer number 484, was one of the highest decorated ships of the US fleet in WW2 with total of 16 battle stars. Although it participated in many battles and operations on Pacific, it has never been really damaged by enemy fire. Still, she was damaged several times, first due to friendly fire (Oct '42), then she ran aground on Guadalcanal coast (Mar '43), then collided with anouther US ship (July '43) and finally was damaged by typhoon (Dec '44). At the end of war, DD-484 was sold to Turkey who didn't leave a scratch on her for almost 30 years.
487 is the number of the MS Dresden Codex 487, which is a German fencing manual created in the early 1500s. The manuscript is a compilation text consisting of treatises on a variety of martial topics, by several different masters who stood in the tradition of famous german fencing master Johannes Liechtenauer.
Although it seems there are lot of options for 494, being a nice palindrome number, my pick would be year 494 BC, when The Battle of Lade was fought, and that is naval battle which occurred during the Ionian Revolt. It was fought between an alliance of the Ionian cities (joined by the Lesbians) and the Persian Empire of Darius the Great, and resulted in a decisive victory for the Persians which all but ended the revolt. Although victorious, Darius vowed to punish Athens and Eretria for their support of the revolt and decided to start preparing for a campaign to conquer the whole of Greece, a campaign that resulted in legendary Marathon Battle, Battle of Thermopilae and Battle of Salamis.