tail lights on an oval

just to lay this minor ordeal to rest, I followed Olli's & Speedy Jim's advice and also re-read Bentley's section on tail lights. It appears that the bulb holder is grounded by it simply sitting firmly in the hole to the reflector. However, neither of my holders will stay securely or tightly enough in the hole to make a ground. I'm not sure the purpose of the copper piece that comes off the bracket that holds the tail light housing to the fender, but thought that it may be involved in someway - but regardless, I am in the process of using a jumper wire for a ground as that did the trick when testing, giving a nice bright glow when the brake was applied. I now have to come up with some simple rig to make sure the bulb holder stays in the reflector hole. - DB