What will the gauge read when set to the proper barometric scale? 50, 60, or 64 feet?

That depends on what the people in the calibration shop did to it. My
understanding is that the =installation= is certified. It would be
logical for the certified installation to be calibrated to the wheel
height. It would be equally logical for it to be certified to the
instrument height.

It's an FAA certification. 'nuf said.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.