Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Yes.  I think there was a time when the two websites each had a different focus. That appears to still be the case with some of the stuff they carry, which doesn’t fully overlap.  But they’re moving mostly the same stuff, under their various brand names.  This engine alone has been hawked as ENJOMOR (same brand as the recent DOHC four which is also marketed as “HMANE” and “guangsu”, depending where you look), and the newly appearing MUSA brand on the cylinder head of the complete engine.  Another engine I own, their water cooled vertical hit and miss, is variously marketed under at least three brands and model numbers. It was apparently designed by office of steam member “Jin”, and sold on his personal microcosm website as well as enginediy and stirlingkit. He is brains behind several of their small engines, and had at least some involvement with modifying their impeller water pump to market with this engine as well.

A clue is the “about” information on each website. It’s essentially cloned.