Aging brain cells
John is my excuse. Checked with one of the people and his reply
I personally never flew it single engine with passengers. To do that deliberately would have been against all regulations.
It was done occasionally on long distance ferries crew only, where fuel was critical and I have done that. You would fly twin until the overload external tank was empty then shut one down. 25% sounds about right. The machine flew slowly, maybe 100K single or twin. A very good single engine machine. I flew it back from the Scott reef on one when the number two had a runaway up. We were at MAUW, 13600?? and she just waddled all the way back. 180 NM as I recollect.
Part of the conversion was to go to 3000 (I think) and shut an engine down, set it up for restart then pull the other to idle. It was then a matter of entering auto and getting the shut down engine on line. As I recall (it was over 35 years ago for me too!! ) you could be up and running by 1000 feet. No big deal. It was Mayne Bristow by the way.
Nearly time for morning tea, better park the BMW and have coffee and cake.