Ha! It runs! Amazing what you can do with copious amounts of carb cleaner, mineral spirits, and a six-pack (or two) of beer. And patience. LOTS of patience.
The stuff in the crankcase was home-brew grease. "Home brew" because it was what was left after the rest of the oil had been consumed. No oil changes for this baby in the last several thousand hours.... just "top offs" using whatever happened to be laying around (confirmed by owner). I used a long-handled teaspoon to scoop it out as it had the viscosity of cold pudding. Once I got the worst of it out, mineral spirits got the remainder flowing again.
The space in the thorax of this critter (where the pushrods pass through the jug on their way to the rocker arms) was also completely gooped. Again, patience, mineral spirits, and much cussing with a toothbrush got the job done.
The overhead bits were actually in quite good shape. Again, turps, beer and elbow grease were constructively applied.
Happily, my earlier belief that the injection pump was munged wasn't true. The injection system wasn't shot... just completely gunked. Turns-out a 50/50 mix of ULSD diesel and Marvel Mystery Oil is a soverign purge for an injector pump. Once the (old, unfiltered, fresh-from-the-crankcase) waste motor oil was flushed-out of the injection system, it got to feeling much better.
After fabricating a hose-fed cooling system and filling it up with oil, it caught fire on the second try. It was NOT happy, but it ran. I spent Sunday tinkering with the various bits and feeding it clean diesel laced with various OTC cleaners. By sunday night, it was starting and running happily. There is smoke in the exhaust, and the injection pump leaks, but it runs nicely and isn't bad for vibration once it's up to speed.
Now comes the actual tear-down and rebuild.
Question: I've looked using all the search terms I can think of but can't find Vidhata parts anywhere in the USA. Anybody got a source? I really don't want to buy directly from india if I can avoid it.
Roark