here is what David Squirell had to say,
In regard to the engine out performance of the Drover, the mark 3 Lycoming engined version, would fly happily on two and just maintain height (straight and level only) on the front engine only. There was a height loss during manoeuvring!
In the gypsy engined version, I lost power on the front engine just after take-off from Albury. The vibration was so great that I had to reduce power to idle. After avoiding Monument Hill, I managed to coax it to four thousand feet. Considering from this altitude I would be within single engine range of airports on route, I continued the ferry to Bathurst.
In both of the above incidents, the aircraft was lightly loaded.