the address was
(name of person)
KIMa 9 xx (xx is a two digit number)
It's a bit of a mystery since he has never made any claim for a missing item, or given me any reason to suspect it hadn't arrived. I want to get my facts straight before I contact him.
solved - it's a flat number - I think that they must have tried to deliver it but failed, then he didn't collect it from the post office or something. That helps a lot, many thanks to everyone who responded. I've now contacted the buyer and am waiting to hear back from him on ways to sort this out.