My reply to your e-mail bounced, so I'm posting my reply here in the hope that you will visit the blog again and see it:
I hear from time to time from people who have been stationed in Keflavik or who have accompanied their spouses there, and it's always interesting to see what foods they miss (usually the fish and the hot dogs, but also miscellaneous other stuff).
As it happens, both Gunnars mayonnaise and smoked lamb can be ordered on-line through the website nammi.is. The following links will take you to the right pages: for mayonnaise: http://nammi.is/mayonnaise-
and for smoked lamb: http://nammi.is/ss-smoked-leg-
However, you should check if there are any import restrictions either product before you order.
Best regards and I hope you get the chance to visit Iceland again.