That's Right, Derek!
The rebuild date was August of 1934. And although it wasn't that old when it was rebuilt, it was probably traded in for a model 800 or 450. As I said before, that's how the Special program worked. Hoovers that were traded in for newer models were rebuilt at the plant, then sold as a Special at a considerably lower price than their lower priced model, so that those who couldn't afford a new Hoover could buy a like-new Hoover Special.
As Jimmy said, service, repair, and rebuilds of customer machines were taken care of by the local service center, and the factory rebuilds were for resale.
Jeff