Acoustat 2+2 HF Control on Interface

The high frequency controls on the interfaces of my Acoustat 2+2's are not working. I've been told that some fine sandpaper and contact cleaner will clean the contacts on the rheostats and correct the problem. My question is this. Would it improve the quality of the top end of the 2+2's to disable the HF controls and bypass them altogether. I've always had them set to maximum anyway for the best possible sound. Any knowledgeable advice is appreciated!
Removing contacts from a signal path will always make an improvement in conductivity. That's inescapable.
Hi Eddie.  Would you contact me about using servo amps from Acoustat x on my model 6? John 

Always been a fan of the Acoustat 2, best sound I got from them is when I made a new frame for them and turned them into 8ft tall 1+1, imaging became 10 x better. 

Here is the schematic, if you need it.