If my IA determines that screwing a bit of plastic onto the instrument
panel (using the existing mounting rails with approved hardware)
constitutes nothing more than a minor alteration, can he simply make a
logbook entry and sign it off? What other paperwork must he execute, if any?

Mike, I can't quote you chapter and verse -- but I know a guy who
*can*. Call Tony, at McCandless Aviation in Waterloo, Iowa. He's the
head of their avionics shop, and he did my installation with a logbook
entry. His number is 319-232-1234

Once done, what happens wan an FAA critter with an attitude problem at
some remote airport where I am not based comes along, peeps in the
window and says "where is your paperwork for this thing"?

I've only been ramp-checked once, but the FAA dude was only concerned
about your paperwork (pilot certificate, medical) and the aircraft's
basic paperwork (airworthiness cert, etc.). At no time did the guy
even look at the panel, other than when he looked in the plane at me
and Mary.

I have a hard time imagining a situation where an inspector starts
asking for STC and field approval paperwork on stuff like the AirGizmo.
Hell, it would take me three hours just to show him the paperwork on
all the other mods on my plane. (Let's see, wing tips, wing fillets,
landing lights, flap gaps, aileron gaps, fancy pants...shoot, I'm up to
three hours already!)

IMO, you'd have to really pee in someone's Wheaties to get ramp checked
THAT hard.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"