Dual Gauge illumination

Listers,
 
I just bought a dual gauge for my 1500. It's an early gauge with the
temp marks numbered. There's no provision for a bulb on the back, but
there's an opening in the housing at about the 10 o'clock position right
behind the bezel. Is this where the light would go? Where would I find
the right housing?
 
Thanks!
 
-=Chris (resurrecting the rollover!)
Chris King 
http://home.comcast.net/~kvcbk/