No unfortunately this is something I have tried a number of times on various mods and even on custom made models assigned bump maps in the proper mapping slot but it never showed in game . Not having the devs help with this one it’s just a guessing game, however if you know of anyway take a stab at it maybe you will figure it out
My best guess is it’s dot3 and with the help of a .DDS photoshop plug in from Navida you may be able to replicate the other few bump textures in game, the channels look very odd to me when I was inspecting them closely.
I believe the .DDs filter can be used to output a bumpmap of your texture
The plug in + info is here , good luck