Hi Jeki Jock,
I flew Islanders in the Falkland Islands for 10 years, the fleet consisted of six 260hp aircraft. As I mentioned on my earlier post the poh gives a drift down stabilising altitude of about 2400ft in ISA conditions. I was fortunate enough never to suffer an engine failure at all so my experience on one engine was always under test. At max weight they all climbed like pigs on one engine (all airfields in the Islands are below 500ft amsl). During Base checks or air testing we would do an actual shutdown and we would only maintain altitude at a light weight.
As you say though every aircraft is different and we are only humans in the front.