PROBLEM W/6 POSITION TONE CONTROL

[ksl]

Hi all & I hope all are well,,, I just got my BOGEN HE-10 back & it's running great, but on the 6 way tone control knob pictured, needs something. The first 5 positions from L to R, offer different degrees of bass, and totally kill all the high end smimmer that one expects from single coils w/no high end string definition,,, But the 'Brilliant' is especially cool, but incredibly bright. Comparing all 6 preset tone options, the Brilliant is the only real true usable position, and if I'd like to somehow tweak it, and tame high end ever so slightly, while injecting some low end that, and give me the best of both spectrums. So, looking at the schematic, could someone suggest kindly some simple component value changes that would round out that 6th position, since the other 5 are useless? 

Thanks & be well~
Kenny.