Driving Mercedes diesels for over 20 years I have seen it all.
Sprinters come on the market over 20 years ago and 18 years ago I was admiring motorhome conversion in France.
Cargo vans in Europe make 2 million km without pulling engine covers.
Than we had Mercedes becoming US corporation, than Sprinters were manufactured by Fiat, now they build them in Argentina ????
IMHO when changes on corporate levels had some bad effects, it is US mechanics who could never learn how to work on small diesels.
Been going like that whole life and that is why we have so little diesel sedans in this country, while my dreams - diesel wagons delivering 40 mpg never made it here.
I DIY all the service and changing oil on MB cost me less in materials than on my Ford, while Ford oil change takes crawling under the truck and even with Fumoto valve it is nasty work.
I can change the oil on Mercedes with electric pump, while wearing white gloves and never bending down.
Like I said before, I know the drivetrains and OM651 engine is a marvel, when even the OM642 V6 diesel delivers lovely performance for higher maintenance cost.
I will read your Turtle III blog later to get more ideas what exactly I am facing, but looks like you took the hard way of converting cargo van, when I am trying to get it easy with bus version. That will make the paneling, insulation, HVAC already there while the window all around will not put limits on my floor plan
And again, I am using camper interior, so don't have to build anything major from the scratches - just adapt what I have.
My friend in Chicago just spend $80k on Sprinter conversion and he'll be coming to Vegas in few weeks, what will give me good opportunity to measure everything.