On improving Le Passific 2SK170 JFET MM RIAA Pre by Walter, Hiraga?

According to the trusty Tube Preamp CookBook - Allen Wright, while disc cutting treble is not increased above about 50KHz so while playback the inverse RIIA network should stop decreasing above 50KHz. So a resistor should be added in series with the capacitor cutting high frequency on passive networks. See Chapter Circuit Modules...Passive 5. This should give more air and life to the precious vivyl records. How would this neat trick sound on a DCC90 (3A5) Pleiades battery powered RIAA electron tube preamplifier?. How would it look made from plexiglass? Would an MC to MM stepup be needed made with transformers inside Neutrik modules, cylindrical or rectangular for example? Vinyl makes better men (women) of us all.