Recently purchased an ailing 1979 300D. Never even looked at one before. Was elated to see the Bosch pump,-- Like a trip way back in time.

Thanks to the wonderful info contained here, and in my old, and feeble mind,-- got it tricked out in one weekend.

Delivery valve o rings, primer pump o ring, some new fuel lines, and filters, plus a little valve, and timing chain tightening, and pump rotation. Also remembered an old trick,--added a low pressure electric fuel pump to aid the old, and worn supply pump, making sure "Ole Bessie Bosch" has plenty of availiable fuel.

Thanks Fellas, got a nice ride cheap!