Originally Posted by Chombi

A little bit newer, but the (IIRC) French made"Wonderlite" headlights were a very common thing bought by cyclists in the early 80's
It's a rectangular shaped headlight with a white and then later, different colored plastic case that clips on with a nylon clamp/bracket to your handlebar and can be slipped off it's mount to use as a handy flashlight. Had them on my bikes when I was in college and thought bach=kl then that they were such a modern cool design for a headlight. Not as impressive to look at today if you can even find one, but it did represent a certain time for me in cycling. It might be appropraite enough for a 70's bike as they could have been available as early as the late 70's.

Chombi