Made a reskin for the Brass Beast, but I'm having trouble. The environment mask I'm using doesn't want to seem to work, but instead the alpha channel of the diffuse (or something else entirely) is being used despite having $basealphaenvmapmask commented out and $envmapmask pointing to the texture I want it to use. I'm not using $bumpmap either, so I don't know if this is me screwing up somewhere and not realizing it, or an undocumented bug in TF2's branch of Source. Here's my VMT.
I know it's not working because parts where the envmask is black clearly have a reflection in-game:
The white areas are supposed to be copper and the black is supposed to be Valve's albedo coloring, sans reflection.
If anyone was curious, it turns out $basemapalphaphongmask being set to 1 also forces $basealphaenvmapmask to 1 (unless $normalmapalphaenvmapmask is also set to 1, in which case the whole specular mask fails to load spectacularly and you're left with a fully reflective model). Even if you manually set $basealphaenvmapmask to 0 and declare a separate environment mask, the separate mask is ignored as if it wasn't in the VMT to begin with and the alpha of the diffuse is used in its place.
It doesn't look like this particular issue is addressed anywhere from what I could find, including the Valve Developer Wiki.
I don't think there's any way to separate the Phong and the Enviroment shading using material commands in TF2. The only thing I think you can do is to edit the model to use a different material that doesn't have $envmap for the parts that you don't want to shine.