I left a mesage with Briggs in Brisbane and they got back to me. They claim that only some of the horizontal motors have been made in China and only in the last few years. All vertical motor, of which this is have been made in the USA.
It is one I haven't seen before in that it has a panel type air filter which sits flat on top of the carby. The engine speed and choke controls are mounted on the engine so it has no handle bar mounted throttle. As you have said Grumpy it is a 3.5 HP. If they have engine controls on the engine itself are they usually for pumps or mixers etc or they can be adapted to anything?