To do this I would use a 'blast from the past', a variometer.
This consists of two coils, one fixed and one rotating inside
the fixed coil. If both are the same inductance (so the outer
one is would with wider spacing than the inner) when they are
in "series aiding" the total inductance will be the sum, plus
the mutal inductance. When they are series opposing, the total
inductance will approace zero. (over simplifcation).
Variometers have NO moving contacts so they are easier to build
than rotary coils. They can't be made as large in inductance
without avoiding other problems (large distributed capacitance),
but a small variometer in series with a multitapped coil is a
good compromise.
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Don't know the US situation ,but in Europe the marine 2 MHz band (in
particular 2182 kHz emergency channel) is no longer used, with most ships
now having satellite comms.
All that redundent equipment is now being dumped or made available via the
surplus trade . They all have variometers. However these variometers are
probably only usable up to 10 MHz.
Recently I was given a low power life boat emergency transceiver made by
SKANTI (Danemark) for operation on 2182 and 8863 ? khz ,fitted in a water
proof enclosure ............beautiful components including a variometer.
Skanti also made the wellknown Sailor marine radio ( painted green).

Frank GM0CSZ / KN6WH