i tape them to index cards and write the winner a thank you note than send it like a regular letter. I have never had an issue, but with the 6g I would put a second stamp on or you could send it to someone with one and see if it comes back or not to determine if you should put one or two stamps on it.
Is there any way I could just buy one off you? I could still bid on this one to raise the credits or something. Or maybe if you know where I can find one besides a piercing/tattoo parlor ?