Black Rinalda Kidd,
I see you have already met our dear freind Capn_Enigma. Here is a link to one of the threads he was disscussing,
http://pyracy.com/forums/index.php?showtop...642&hl=ear+ring
It doesn't address your question directly but it does lay out a really good argument (one of many) for ear rings in general not being period. By way of a more direct answer to your question I have no refrences to sailors wearing copper earings but then given the limited number of refrences I have this should not surprise anyone.