You are correct! It is a Bushwakka but not a model I have come across in the archive, probably a rare yet not expensive machine. Worth buying as it’d be useable and interesting too.
I have a contact who knows the buyer of this one with the Tecumseh engine (looks like yours has a Briggs & Stratton engine) he thinks he bought it new so I may get some more info if I am lucky. If I had a mower museum I would certainly want one of these in my collection. As for selling, they are quirky enough to very well in an eBay auction.
Regards Norm.