Ian, your top schematic, "STANDARD BAXANDALL" is nearly my favourite Baxandall variant. It is variable shelf with turnover changed with a single cap. I need to find my notes for exact details of the curves.
It was my first foray into 'exact' frequency response measurements with the measuring chain calibrated and my home made Wien bridge oscillator laboriously calibrated against a recently tuned piano.
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Instead of evil inductors, why not have a cathode follower drive the Baxandall? This is at least the equal of an inductor for 'hand carved by virgins" cred and confers other advantages as well. The Baxandall itself is Lo output Z and can drive long lines & evil loads .. as pointed out by the Great Guru himself.