The first kind has a poorly inset logo on the back with plenty of flash around the die inset, just like the Eagleluxes. The Thunderbird of the logo has very sharp angles to it. It also has eight (four on each side) bosses or ejector pin marks inside the signal.
The second kind does not have the flash around the logo, the area is clean and smooth. The Thunderbird of the logo is slightly redesigned with smooth corners and no acute angles. Also the eight large bumps inside the signal are not present.
Two styles of reflector pans as well. The one on the left is plain. The one on the right has a lot of small square "tabs" punched in the reflector bucket rim to be little fingers to catch the mirror bowl.
Westminster, CA.
