2006 Rickenbacker 4003 tone control question

[mc900ftj]

Recently acquired.  Question for fellow late-model Ric owners: One thing that puzzles me is the taper of the tone controls (but this may be normal for a Ric)...there's very little impact on the tone when you roll them off until you get almost all the way down...and then the highs roll off very quickly in the last 20% of the knob's travel. Both pickups' tone controls are same in this respect.

Trying not to overthink it....I'm really just curious about the fact that they are not as "linear" as other passive basses. Specifically if that's normal for late model 4003's. Said another way, is my instrument defective or is the behavior to be expected from a stock late-model 4003?

Guessing its normal, but I appreciate any input you may have for me. Thank you.