Combo/Temp Gauge Lighting Configuration, Using "Blank" Indicator? Options

[FlacaProductions]

I have a combo gauge with integrated temp gauge (914 641 101 50) and I'd like to use the blank indicator lens position. Has anyone done or had this done?

My "additional/unused" indicator position already has a red lens in it which is held there by a piece of solid black tape. It appears OEM and I have seen others that look the same.

At first glance, you could just remove the reflector, (snip it out or bend it out of the way?), remove the tape and glue the lens in, fit a boot, insert an applicable lamp/lamp holder in the existing hole and be done...but that would then eliminate the gauge overall illumination. That's no good.

My next thought is to get an additional "boot" like the other indicators, cut it down so that it fits under the reflector, insert a small LED (secure it with silicone?) and route the wires through an existing screw hole (leave that screw out and fill it with silicone, etc) or drill an additional small hole. This would illuminate the lens (which is already red in my unit) but retain overall gauge illumination.

Thoughts?

Where can I get a couple of the rubber "boots"? It would involve some trial and error knowing me....