Adding the two band bax alone is worth considering but that alone doesn't do too much. I've done a picture of the sim with the volume adjusted to compensate for losses and I apologise for how hard it is to see The spot around 800-900Hz will be normal. You can end up losing a lot more bass by turning the bass control down, similarly more treble with the treble up. You can get comparable results but the only advantage I can see so far is the mid-scooping with both controls up. You need to adjust more than just the tone stack to get more usable tones out of it and honestly, putting a substantial amount of treble more out of it isn't probably that smart of an idea.
White indicates the original BMP stack, the red lines indicate the Bax stack with volume output compensated. This is the response at the output.
http://i.imgur.com/FMdbETi.png