if we could please ask for your help as well, if you have a free moment, we’d like to learn as much as we can about Environment Lights, especially for Bronze & Iron Age weapons and armor.
The environment lights textures are in the shared folder. Most are packed in the FPK.
"environment_fx_bronze.dds" and "environment_fx_greymetal.dds" are the most used. Nearly all the units use either one of those, or a combination of the two. There is also:
destroyer_environment_light-1.dds
enviroment_light_white_64.dds
environment_fx_bluemetal.dds
environment_light.dds
environment_light_brass_64.dds
environment_light_white.dds
environment_light-1.dds
There is also Final Frontier one called "Environment_FX_Space.dds" It is gives a subtle rainbow like look. Bluemetal and brass are good alternatives to greymetal or bronze. The "bronze" is strongly colored and looks more like gold. The others are kind of meh... IMHO. I would use them if you made the gloss texture too bright since they are hardly noticeable otherwise.
These are all in the shared folder. So, no need to actually include them with the unit. You could also use the FF "FinalFrontier_Damaged_State_All.dds" for the damage texture of Modern ships to avoid having to pack the texture with the unit.
To make a gloss map I have identical procedure to topsecret. Desaturate, play with contrast/brightness, and filters like enhance or bumpmap (makes it look more 3D). It is easy to overdo it.
I've never used a mask file with units. I think you may have to use a LH shader for that, but I've never tried.

You could always just tint the normal diff texture.