tips for aiming headlights

Very interesting read Dan, thanks.
Back in the day when I had my first Demon, (1975), I bought it used and the lights were a Halogen set. They had a dead flat surface and were very bright. The thing that I really remember about them is that when on low beam, there was accually a line where the bright light stopped and then diffused light was above that. If that makes any sense to you. I want to say they were Bosch, but can remember for sure. Any idea what they might have been because other than my off road lights I had on one of my trucks, they were the best lights I ever had.

Jack