OK, so here's what I did:
(1) Removed all the bulbs, refractor lenses, "circuit boards", wiring and other stuff from the housings. Took them down to bare metal. I then wire-brushed the heck out of them and dunked them in POR-15 "metal ready" for several hours to get rid of all corrosion, pitting, scaling, foreign material, etc. Once this was done, I painted the exterior of the housings (including the back covers) with POR-15 paint and then treated the inside (where the bulbs go, behind the lenses) with four coats of special aluminized paint. It is worth noting that there are several varieties of the tail light housing assemblies - some have a white color on the "compartments", others have a silvered coating. The original ones (see above) off my car had the white, the housings I bought off of Ebay had the silver, but it was badly corroded and damaged in places that it wasn't worth saving. My aluminum paint obviously won't be as reflective as the metallic chrome coating that originally lined the housings, but it's fair. Also the LEDs I'm using are more directional than incandescent bulbs and will direct almost all the light back towards a following vehicle. As such, I don't see a problem with this. Here's the finished product exterior:
Another shot of the exterior - I left the inside of the rear part of the housing uncoated deliberately. For one, it will be sealed with a new rubber gasket once the back is installed, so no need. For another, there are a couple of ground points inside the back area of the housing that need virgin metal to contact against. Obviously any surface that will be in contact with the open elements gets treated.
Shot of the inside surface behind the lenses. This is the aluminzed paint. Works pretty well and seems pretty durable. Should last pretty much forever given that the LEDs going in will generate very little heat and they will be sealed from the outside by new rubber gaskets between the lenses and housing.
The inside showing the LEDs installed. I ordered them from superbrightleds.com (no affiliation). The part numbers/prices are as follows (subject to change, but this is what they are today 4/22/08):
Tail/Brake Light - Red/1157-RLX5 ($29.95 each)
Reverse Light - White/1156-WLX5 ($29.95 each)
Turn Signal Light - Amber/1157-ALX5 ($29.95 each)
Running Light - BA9s-x-x-12V, 120-degree wide-angle Amber ($0.98 each)*
* = see note below
Please note that the above also fit for EURO lenses. Obviously if you're using U.S. spec lenses, the colors would be different (no amber, I'd substitute red for all the other bulbs other than the reverse one).
Another view, showing the smaller "running light". Another thing worth noting is that there is supposed to be rubber or felt "pads" that sit between the metal compartment separators and the back of the plastic taillight lens. These got so deteriorated over time (both on my set and the replacement set I bought) they were worthless/crumbling. I had to scrape away what was left of them to paint the interior of the housings with the aluminized paint, so I got pieces of spare black purosil vacuum hose I had lying around (from my 944) and cut them to length, then made a lengthwise slit. They fit perfectly on the ends of the metal separators and do three things:
1. They seal light leakage from one compartment to the next
2. They cushion the back of the plastic lens from the metal separators (might crack otherwise)
3. They look nice.
And now to test. I installed the new rubber gasket and new Euro lenses (remember, I was replacing my U.S.-spec lights with Euro). Looks pretty good:
Red tail light (I tested these all with a 12V regulated power supply in sorta' dark conditions so you can hopefully see the color. They're all pretty bright with the exception of the amber running light - more on that below):
