All the time I was working on my taillights, I thought, I ought to go get my camera and take some pictures - I'm sorry I didn't - just couldn't stop while I was working on it.
Anyway, here's a sketch of what I did. The upper lamp is my stock ERA single lamp, which is essentially the same as a Lucas lamp. The lower lamp is the new Superformance lamp with two bulbs.
I made additional modifications, as mentioned earlier, by opening the hole in my fender to gasket size (indicated by cross-hatch on lower picture, using the more 'open" ERA gasket (from the top), and trimming the divider out of the SPF back-plate (shown by cross-hatch in lower picture. In addition, I used a Halogen bulb in the lower position for brake lights.
I cannot recommend to you to modify the SPF backplate as I did - to do that, you must take apart the lens/backplate/bezel assy, and then put it back together again. This assembly is held together by small bent-over metal tabs on the chrome bezel. I don't have to tell you what happens to the little tabs when you try to bend them out, then bend them back over again
Hope this helps clarify things.
regards,
Jeff