Hughes & Kettner Metal Machine Help !!!!

[rockford]

looking for some advice on this circuit.  Overall, the preamp has good tone and is flexible. However, for me it has REAL overbearing treble response. I want some feed back on how to make some minor mods to reduce high end response, beyond turning treble pot down to 0-2.
I read somewhere else that there is a bright cap on the 1st ? volume gain control. Please chime in. is this the 47p between TLo71 and TLO81, or is this the wrong spot. also, can someone point out the Location/value of treble cap on the treble pot on tonestack ?  Any straight up input would be appreciated.