Hey there, Dad 'n Ivy!
First, thanks so very much for all the valuable input! My apologies for the late acknowledgement - am Down Under at the moment and sort of out of touch. I'm now beginning to put together some pieces of the puzzle...
So, by way of additional relevant info... The car was born in San Jose. I'm guessing that, at some point in its CA life, the 289 A-code engine (more on that in a moment) was swapped out out for a 302. Hence the California BAR tag. That probably also prompted the dual vacuum diaphragm, Edelbrock 1406 carb, and "holey" closed emissions air cleaner.
Sometime after the swap, the car migrated to the Deep South. I picked up the car in SC a few months ago and shipped it off to my son in L.A. He is now in the process of rejuvenating it.
We have a fairly high degree of confidence that it is a "factory" GT. The data plate looks to be original and matches the VIN on the fender apron. Pretty much every piece of sheet metal has an appropriate date code stamp. All of the GT-specific check boxes are there: correct-functioning fog lights, correct curve in dashboard under speedometer, beefier sway bar, correct front disk brakes and master cylinder, exhaust reinforcement panels under rear seat, correct dual exhaust system, reinforcement crush tubes in rear frame tunnels, and so on. Yes, the engine isn't correct. Yes, the carb isn't correct. We're OK with that, though. We'd just like to get it closer to "66-ness" if we can - at least make the air cleaner, carb, and vacuum diaphragm correct.
As for me personally... I have a '65 GT convertible that is my pride and joy. Being in Boston (actually Charlestown, Dad :wink

I don't get to enjoy it as much as I'd like. But now that I know I have a guru nearby, well things are looking brighter and brighter. Beers on me.:smile:
Regards,
-Bob-