Hi Michael
I had a 3053 purchased in the late 60s and another one purchased 2nd hand in the 80s. Both had the lower light conduits (Lichtkörper) glued to the frame. When there was too much glue, the light output was sharply reduced.
How to remove them? You have the remove all the excess glue you see and then pull away from the extremity while pushing gently on the light conduit extremity (ressembles a headlight).
Warning: old plastic breaks very easily.

Replacement: try to find light conduit (plastic fiber optic of the same diameter as the "headlight". Bend it by getting the fiber optic, close to a soldering iron so it gets warm and bends easily without breaking.


I did this on my Micheline 3624 front headlight


Here is the inside of the Micheline 3624



Cheers
Jean