i would sayy.. more than likely.. someone slipped off the crossmember with the jack and that is what munched the oil pan
by munching the oil pan the oil pump pickup & mesh has broken and cracked and left many shards of metal in the oil, then that nice metal filled oil has gone through the motor and shagged out the bearings and got dam hot therefore seizing the engine
well that's my theory anyway, be interested if you tear it down to see what you find
and yes awesome mk1 you have there