You mentioned Florida. There are several manufacturers there. They seem to like the east coast. Grumman is building the Hawkeye in Jacksonville.
I did a bit of a factory tour a couple of years ago for light aircraft, although I had no luck with Piper(they had been very hurricane damaged from the previous year).
Unfortunately Four Winds Aircraft in New Smyrna Beach has closed down. After touring Cape Canaveral head south to Merrit Island. It is home of Comp Air. 250 dollars got me a factory tour and a flight in the Walter powered turbine Comp 7T taildragger. It is a beautiful view from the air compared to the fairly boring ground views of Florida. You can see the nearby space center and barrier islands and intracoastal waterway.
Comp Air,* Composite Kitplane Manufacturer
Nearby in Melborne is Liberty Aircraft. There was no charge for a demo flight. I flew the whole flight on this flight, takeoff and landings. I didn't see the actual assembly plant. Only where the newbuild aircraft were stored.
Liberty Aerospace
Farther south is Sebastian Airport and Velocity Aircraft. 130 dollars got me a factory tour and a demo flight.
Velocity Aircraft
There are a lot of manufacturers in Texas. I only have experience with three. Lockheed in Fort Worth will give a tour if and only if you are a resident of the U.S. Lockheed in Georgia by the way might give you a tour. I got a personal tour of the C-130 and F-22 lines but I was current on the C-130 at the time and that seemed to be the key. Gulfstream in Georgia, by the way, several years ago told me that tours stopped after Sept. 11.
Back in Texas, I just drove up to American Legend Aircraft east of Dallas in Sulpher Springs and got a tour of the Cub manufacturer. It is cool to see a final assembly line of yellow Cubs.
American Legend Aircraft Company - Home of the Legend Cub
Finally, northwest of Dallas by a couple of hours in Olney Texas is Air Tractor. They are friendly and have quite a large facility to build all their agplanes.
Welcome To Air Tractor | airtractor
Usually, the smaller and farther from the big city the manufacturer is, the friendlier they are. Mix the tours in with museums. Now maybe you can give some tips from your experiences.