There is not much info out there on this engine from my searching so far.. I am interested in finding out the rpm and hp. Strange how they did not stamp that on your engine plate..
At first I thought it is direct drive, so to get 50HZ in england it would turn at 1500 rpm provided it was a 4 pole gen head.
However this is not an AC type head. As far as I know and from what I have read on this thread.
It is DC so the engine may turn 600 rpm but the generator would put out 120v DC.. So speeding it up will increase the volt output I imagine.
Inquiring minds want more info on this setup.. It is an interesting setup.. Please let us know when you find more info on your new toy. Thanks.