RB wrote:
"What is the likely Z range such a circuit might match?"

A coil in parallel with a variable capacitor can be tuned to offset
reactance in the antenna. At resonance, a parallel circuit with a high Q
has a very high impedance.

Edmund A. Laport in "Radio Antenna Engineering" writes on page 310:
"Experiment has shown that the correct termination of a long-wire in
this manner (low-characteristic impedance wire to maximize antenna
current) requires a complex impedance and not solely a resistance. The
terminal impedance is of the type R+jX. The inductive reactance can be
obtained from the extension wire by making it longer than one-quarter
wavelength. This means that the correct resistance, obtained by
experiment, must also be located in the correct place along the wire,
and that the correct location is more than one-quarter wavelength from
the end of the wire. The resistance has an order of magnitude of 400 to
600 ohms in many cases, and 500 ohms is suggested as a starting place
for trials when the antenna consists of a single wire. The reactance
values required usually should be between j150 and j250 ohms, so that
with thin wire, the extension wire whould be somewhere around 105
degrees long."

Best regards, Richard Harrison, KB5WZI