Paul Smedshammer wrote:

Lessons learned, 1) do not fly VFR Over the Top unless you absolutely have to
and if you do get a lot of altitude so you might have a chance to glide to a
clear area to land and 2) really work the wings and sump the tanks vigorously
after rain or even dense fog - or for that matter anytime before you go flying
- you might have trapped water in the wing somewhere.

You didn't mention: (since this is a Mooney) check or replace the o-rings in the
fuel filler caps frequently, perhaps twice as often as required by the AD. Also
check for corrosion of the cap mechanism preventing the o-rings from sealing
properly.