i think you have just the reflector.
you should be able to install the oem lighted one, or modify yours to install a 168 or something. you can probably drill a hole in the area where the bulb goes on the lighted one, and use something like this.
Auto Meter 3211 168 Replacement Bulb & Socket for 2" and 2-5/8" Gauge : Amazon.com : Automotive