I've not seen this one either. It looks exctly like the Shag Rug tool - without the row of nine 2" protruding chrome comb nozzles, and yet they also don't appear to be just left off - with that finished off bottom plate. Also, my shag tools all have 2" wheels and your's look smaller. Definitely the same upper body casting.
I'm gonna speculate it's a variation designed for less-than-shag deep pile luxo carpet Elux-o-matic tool.
I'm betting Doug Smith has the answer...
Dave