I think you ought to be warned before some officious person asks you why you're wearing a key (singular) at an SCA event. A Silver Key and a Gold Key are registered SCA heraldic symbols, and have a specific meaning attached to them. Go ahead and wear at least two or more keys, but wearing one might get you tagged as a seneschal or one who can provide loaner garb.

That exact thing happened to me once. I added another couple of skeleton keys to the one I was wearing dangling from my belt and all was fine. This is one of the sillier things that happens in the SCA-- running afoul of non-period symbols associated with ordinary objects. Just don't get me going about colored belts...