Okay. . .took the exterior cover off and inspected.
It is an Airxcel product (Coleman).
There are no drain holes for the forward high side condenser coil.
There is a sort of tray. . .non removable beneath the coil.
The tray exhibits what looks like residue from water evaporation.
No drain holes visible in the tray.
I reassembled it and ran it for a little over three hours yesterday.
No drips.
But this is currently in 12% Arizona humidity.
It was leaking in the 80% + humidity of tropical west coast of Mexico.
I suspect that this particular AC product cannot handle very high humidity - the drip tray simply fills up and overflows.
(The grill has controls and electrical connections - removing it while running is not a reasonable option for my technical abilities.)
