On MB5s, I run Type F Transmission fluid in the bottom end since it less thick than most of the oils and provides enough lubrication.
On the headlight, you should be able to use the stock housing and jam one of those circle Sylvania halogen headlights 12volts into it. It will be a tight fit but looks good. Then adapt your wires to the 3 prongs on the headlight.
I think they just inherently vibrate alot. Like can't see out of the mirrors when banging 10k. They sell anti-vibration gloves.