Thanks for the info. I'll take mine down soon to check. I bet it's chrome inside. I'll try the wire brush wheel on the topside to eliminate the chrome. At least they're kinda cheap if i mess it up.
On a side note, kinda related... One of my front marker housings on my '68 was very corroded on its reflecting surface, making it dim, so i lined it with kitchen foil, shiny side out. It's VERY bright now. I did both to make them even. I prob'ly have the brightest markers you've seen they haven't melted yet.
they haven't melted yet.
