Re: 6.0 turbo
If the owner can provide records of regular maintenance, such as oil changes, it might be a worthwhile buy if the price is right. Most C class motorhomes are V10 gas. If you plan to drive this unit often, then the diesel would be the more economical choice.
Keep in mind that the owner didn't have to disclose that the turbo was replaced, so he was kind enough to tell you that at least. Only thing to do is to take it for a test drive. Dealer maintained doesn't mean that he took the motorhome in on time for services, so check.
With 41K, the owner should also have done a transmission service, as a motorhome classifies as a 'severe use' on the Ford maintenance chart as the engine has a consistent 4-5 tons that it's hauling around all the time!
It's also best to get the VIN and check with the dealer to make sure everything is up to date in terms of technical service bulletin updates and computer/software updates for optimal driveability. TSB's aren't always relayed to the attention of the owner, original or otherwise - so ask.
On a side note, if you live in a mountain area or around a lot of hills and will drive it around there, that might have also been another reason why the turbo went, or the owner didn't slow down when climbing grades and maxed out the engine rpm (downshifted as low as possible to keep speed up, and engine RPM HIGH).
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!