Produced at Leavesden by Rolls Royce by mating 0-360 (I think) pots with 0-200 crank.
Ran just as sweetly and reliably as the 0-200 and made a great improvement to the performance of C150s; pity it didn't come in time to be fitted to the Beagle Pup. More powerful than the dreadful Lycoming which succeeded it in the C152.
Don't know about Mogas; I thnk they were meant to run on leaded fuel.