Well finally got around to completing my homemade experimenting. Took a 3D cell Mag and used some old light gells I found in the garage from my old band days. You can get these sheets of colored film cheap at local shops that service area musicians. cut out pieces to fit the Mag's lens and inserted them. Used one of each following color. Red, green, blue, teal. went out with my 1st gen cheapie monoc. results were great! Shining on targets and a stone wall at 50yds, the spot from the light looked about the same as using the Mag without the gells and with the naked eye. Best results when focusing the beam to its tightest. Also, standing in the dark looking directly into the lens of the Mag, no true visible light or beam emmitted. You can tell the light is on, you will see the filament and outline of the bulb behind the lens, but so dim as to be not noticeable at all. Only one downside to this, the weight. I was able to use the mag by resting it on my shoulder and holding it as you would a SF w/ a clickie switch. But this can get tiresome after a while. I tried this setup with soem LED lights but results were unfavorable. Basically you're going to get the same results looking thru the Nv as you would without it, meaning the same amout of illumination of an area/target as that particular flashlight will normally give you.
Tried also a 1 and a 2 cell 123 type flashlight, and they did as well as when used without NV. For the 123 cell lights I am not sure how heat will affect the gells but they should withstand well as these gells are designed to be used in stage lights using 50-200w par floods. Use a little ingenuity and you could probably make a simple on/off device foir applying the gells to the front of the light. Final test, used a cheap 4AA plastic flashlight w/ a KPR 103 bulb in it. except for the expected lower quality of hotspot and being non focusable it put out as much light as the 3D mag. Was also much more manageable to handle and easier to manuveur and utilize. In normal use this little 4AA is comparable to the 3D cell in output and is used alot unless it is a task where the light could get dropped on hard surfaces or experience abusive conditions. I am very happy with this cheap and simple set up. Now I will get longer life out of the AA's that power the NV, and will have the small 4AA for convinient portable illumination, and the Mag for focusable reach.
You can also buy IR-transmissive filters from places like Edmund Optical, but they usually aren't cheap.
Using exposed, developed color film works as a filter for IR-sensors, to keep visable light from affecting them. Scraps are available from any place that develops film (They keep looking at me funny, for some odd reason).