A history lesson in the original Trek :o) There were twelve Constitution Class ships, of which the Enterprise was but one of them. Each ship in TOS had their own crew emblem on their shirts (See Commodore Decker in the Doomsday Machine ep. He was captain of the USS Constellation). The one for the Enterprise was adapted Starfleet wide just prior to The Motion Picture. The USS Excalibur appeared in the TOS ep "The Ultimate Computer". It's captains name was Harris (Captain Harris was the only name given). The character above is my take on what Harris may have looked like (he wasn't shown. Only name mentioned), with the Excalibur crews emblem on his shirt (a swordish emblem)