The car was raced at the 2013 Silverstone Classic by Kevin Musson and was referred to as a Dolphin GBR , presumably to differentiate it from the American-built Dolphin cars. As you say, it was Ford MAE powered.
I've never heard of the car, and I'm guessing that it was not successful in period, and was not raced much. Dave Latchford raced under the Ecurie Dauphin title, and ran a Dolphin-Fiat at the 1960 Monaco F.Junior event, which I reckon would have been one of the US rear-engined cars.