Have you ever watched Survivor? There are always the Johnny Fairplays out there (he made the ploy that his grandmother had died to get sympathy on the show) that will say anything. I would wait until I had the carburetors and everything, before I retracted the ad and made the apologies. Promises can be made, but it is the following through that makes it legit. It only takes a couple of minutes to let someone know.
My 2 cents.
Bill M