The key click volume is adjustable via resistors. I would seriously consider re-capping the generator. All B3s are uneven now, due to the youngest being over 30 years old. Goff has kits available that are pre-matched. A tad expensive, but worthwhile, imo.
When I re-capped my '58 B3, it really smoothed out the response across the manuals. I also cleaned the buss bars, which helped as well.
The RC networks are a must, too.
I just got an A100 for free that has some issues (weird harmonic things when certain combination of keys are pressed) and I'll probably re-cap that bad boy as well. I have not re-capped my C2 yet except for the chorus/vibrato line. It is a very dark organ.