Does anyone know of a 3" OD flush mount tail light assembly. Must use standard tail light bulb. Oh, lense should be red, of course.
On almost any flush mount you will have to at least drill/cut holes for the mounting screws and the socket that extends out the back of the light. 51/52 Pontiac are pretty well the standard for small round flush mount hot rod lights. The guy who bought my 51 Merc took out the 59 Caddy bullets I had frenched in and used the round lenses from a 56 Chevy with some sort of custom base. For something simple but different if you have the room behind the panel what about using 56 Chevy pickup round tail lights with just the lens and bezel showing? All the truck goody vendors have them fairly reasonable. These are on Ebay via Classic Car goodies.
I'm going to the '56 Chevy lenses to see if they are the size I need and make my own bases like Mr 48 suggested.
1950 Pontiac are 3 5/16" if that's close enough? Check United Pacific online catalog for incandescent taillight assemblies: http://www.uapac.com/antique/lighting-and-electrical/complete-incandescent-tail-lights.html
60 to 67 Corvette tail lights are 3"......not flush mount however. I might have a pair of lenses, I used to run them........I just hafta look for them