Racine Salesman's Sample
A gift from a watchmaker friend, this one looks, at first glance, like a complete watch. When it hits your hand, though, you realize it's far too light to be complete. It is, in fact, an empty case with dial and hands glued into a plastic spacer, sans the Schild movement it was made to hold - a salesman's sample, used to demonstrate wares to commercial customers (jewelers interested in carrying the Racine line, presumably). This approach appears to have been reasonably common at a certain point in the industry - I've seen entire salesman's kits, complete with several models in a fitted suitcase, for Rado and Hamilton, and I'm sure other brands did similar things. I'm not clear on how widespread this practice was is or whether it's still common today; I have handled an modern IWC that was mocked up in this fashion, but that was a pre-release of a new model, so that may have just been a stand-in since a fully-finished working model may not have been available yet, rather than standard operating procedure.
I've considered getting a Schild movement and popping it into the case to make a fully-working watch, but I also kinda like the idea of maintaining it in its current state as a testament to this interesting business practice.