ERF-NGC-European:
Incorrect with regard to tractive units. When the SK range was introduced you had to have EPS as Mercedes chose to force the issue by stating ‘this is how it is now.’ It lost them a lot of UK customers, most of whom switched to Scania. I understand that the only SK units to have been released with non-EPS boxes were those that went to the Bulgarian state operator, Somat.
Thanks for clearing that up Robert.As you say I’d guess the rental unit I drove was pre SK.
While obviously didn’t realise that they had a different sales policy regards units v rigids or that there were many other major differences from NG to SK. 
What I do know from experience is that the usual awful heavy shift of the manual 2534 regularly broke the gear shift linkage although double de clutching the shifts helped to a degree.On the one I drove it broke one morning in the yard at Luton when dropping the trailer leaving me stranded there for most of the day with the silly short sleeper before another truck was brought out to me.It had obviously already been welded by the workshop staff previously.