Clearly a fuel supply problem and not likely to be catastrophic.
I'll bet plenty of 616/617 MB diesels have changed hands or gone to the junkyard for similar issues.
My 300SD did not make it home from the seller's location because of this issue. In fact there were a couple of service receipts in the pile the seller gave me where the car had been towed into the shop after it had stopped running. The receipt showed the shop had "reprimed, and it ran".
Turns out the primer pump started leaking (near the end of a 300 mile trip) and the car lost power and then quit. I also had fuel tank vacuum that contributed to the problem.
So, all I did at the side of the Interstate was release the tank vacuum, try to prime the system using the pump, and then crank down the pump as best I could. No further problems and I shortly thereafter changed the primper pump out for the newly designed version.
Got the car cheap - this is probably why the seller decided to get rid of it.
Ken300D