A fellow Doper sent me a link to this recently.
Coincidentally, I was talking with my restoration guy last month, and he mentioned that the B-series engine was common to a lot of BMC cars. By changing the head (IIRC) the engine was used in Austin cabs.
Interesting thing to do to a roadster, but even the gas-burner took over 12 seconds to go from 0 to 60. The seller says it will do 70 to 75 mph, which is a bit less than the Mk.I’s and maybe Mk.II’s 107 mph.