Jeff posted photos of these unusual hubs to Facebook. I’ve never seen a set. It appears they are 10 spline, automatic hubs. The name Powr Matic is stamped in three spots on the hub’s cover. Google searches weren’t any help either. There is a PowrMatic company that specializes in HVAC products, but there’s no evidence that they produced any hubs, though the company was around in the 1950s and 1960s.
So, anyone know anything about these?