patient:
'86 240DL ~250k on first engine, ~350K on second)

context:

I was driving at about 45mph and had to make a quick dead stop. That was it. DEAD! well, at first i just thought that my brick had stalled so i go to crank her up and i hear the engine crank, but no shaking of the engine.

symptoms:

It feels like everything is moving freely inside. no clanking noise, just a smooth, almost electronic fluidity. So, my first instinct is that my long overdue timing belt had busted. Go to check that... intact, but not turning during start. Check my spark... no spark. Check the distributor... not spinning. accessory belts are all spinning. check fuel, no fuel coming through lines(safety shut-off?)

diagnosis:
my feeble guess at this is that my crankshaft is a goner. i may be utterly wrong, and please tell me that i am. If I am not, is the replacement a remotely possible and economical job for someone with a relentless ambition, clever hands, but non-specialized tool set.

thank you to this forum. to all the minds. to all the willing givers of knowledge.

btw, if she is dead, i think you guys know exactly what I'm shoppin for!