Have to agree with Kimh on this.... I'm not sure if he makes them (suspect so) or it's a genuine item that he's 'acquired'. Have asked him anyway on ebog so let's see.
I've always asked for a copy of the invoices to backup the stamps in the book on any second hand motor I've bought for this very reason. A fully stamped book means nothing without the backup of the bills detailing the work.
Edit : Moved from security articles to suspicious activity.