I have a vintage external sun visor for sale for $300.  Although it looks rough, I think it is functional.  I did not clean it at all but I carefully brought it back to shape where it appears to have suffered rough treatment in storage.  I had it entirely apart and restored all the sliding parts to fun ction as they should. The original screws could be replaced as they are rusty but gave me no problem.

The only area of concern was on one side of the 'wing' above where the unit bends to connect with the side mounting bracket.  There is a gash about 2" long that could be welded (aluminum) or maybe even crazy glued. I hope that doesn't sound like a Mickey Mouse repair but it looks much like a narrow cut to the skin you might cover with a band aid. Otherwise, the unit looks dirty but fine.

I don't know the make but after some research, I would guess it to be a Fulton or a Peckat but it could be Dietich, Sante, Fection, Rosco, Holden or Casco.

It came with one badly rusted center bracket and one side bracket, not quite so rusted so I used them to make templates and fabricated new ones so the unit comes with one new center bracket and two new side brackets. The two large side brackets include four small brackets that clamp to the larger brackets. I researched to see how the units connect to the drip rail and discovered that I had to make the smaller brackets as well. I believe no holes are needed to be drilled into the drip rail or roof using these brackets.  I have more photos if requested.  I made two pair of side brackets seen in photo but I am keeping one pair.