Well--

Is everyone assuming that it's dog slow because a cylinder or two has lost compression??

That'd be my concern..

Overheating a diesel, seems to be a much larger sin than overheating a gasser.. I think it relates to the tolerances necessary to run such high compression-- but I'm probably dead wrong..

My little VW pickup blew a headgasket on the interstate, and pretty much comitted suicide.. I replaced the headgasket-- but still was unable to get a 'running' amount of compression.. It may have just taken out the rings, but I got the engine out, before my life had to move on.. It, and another diesel engine that also needs a rebuild sit at a buddys house..

Point is-- I'd compression test it, before giving them more than you think you can sell the thing for scrap for.. I'd also trailer it-- given the distance you're talking.. I think either way, it would arrive to your place under another vehicle's power..

__________________
Agnes (the Limo) '84 300SD
Pearl (the Taxi) '81 240D (preparing for the 'afterlife')
Bridgette (baby girl) '82 VW Pickup-- currently getting readied for her rebuilt (overbored) engine.
1 VW 1.6 NA diesel **not installed in vehicle**
Gidget (the bimbo) '87 VW Cabriolet-- the diesel engine it above is eventually going there!

and a BMW Motorcycle. (1998 R1200C)

Did I mention I'm of German Heritage??