spec, Thanks for the schematic. I'll give it a try soon. I'll only change LEd arrangement to parallel, as I think those don't work well in series (but then again I could try that too )
I suspect you are misreading the schematic of post #18.
The two LED strings shown on the schematic of post #18 represent a single one of your LED units, not many. I now realise that my schematic is open to misinterpretation.