There was a thread waaaaaay back on Dorian's site about lighting. I was interested in this topic about 4 years back as I bought new bulbs for the back end, and halogens for the front
Two things from a quick trawl over there:
"This "top hat" is the bulb shield, yes you must keep it. This helps reduce glare. The bulb shield is on most halogen lamps today, even with the bulb coating.
Just to clarify on what Katman did to those who might not know:
On pre 71 European headlamps, the W113s used a R2 non halogen headlamp bulbs. You can buy Halogen H4 bulbs with a R2 base to replace the old incondesent R2s. The halogen bulbs will increase your vision if your headlamps and lens are in good shape. I suggest adding relays with fresh wires to maximize light output as old wires dont flow as much energy as newer, cleaner wires. Relays can be done without cutting the stock wiring."
And before I bought my bulbs, I had a chat with Daniel Stern - although did not buy from him - he felt shipping would be prohibitive, which was very decent of him
http://www.danielsternlighting.com/products/products.html
