Okay, so here's how it went!
Ended up with two gun vaults (200 and 100; gun and one empty mag in the 200; second mag and rounds in the bullet case in the smaller vault). Both secured by their cables to the handle-bars inside the new hard-case suitcase.
Could not imagine it taking more than 2 hours to get the airport (it's an hour drive -- no accidents, great weather, just dumb drivers, I guess...) so I stopped and called Delta to see if there was a seat on the next flight out. "Yes, there is a seat and it will cost $430." !!!
"Never mind, I'll try to make my flight!"
Got to the airport around 9:30 for the 9:55 flight; the nice Delta check-in lady laughed when I said: "I read that I should be very careful to tell you that 'I need the paperwork for flying with an unloaded firearm' -- they specifically said I should NOT to walk up to the counter and say 'I have a gun.' She said it was past the last check-in-bags time, so switched me (for free) to the next flight an hour later. Got me the red tag and we filled it out. She did ask to look inside the vaults, and I pointed out the mags were empty, but she didn't try to touch anything. Then she sent me to the "Odd-sized and Large Baggage" check-in office, where the TSA (?) lady borrowed my TSA-approved key to open my suitcase in front of me and agreed with me that both vaults were locked (she didn't ask to see inside); swabbed for explosives, relocked the suitcase (returned my key to me), and sent it off into the bowels of the airport....
Turned out I was PreCheck (maybe because I was flying First Class?), so an easy trip all told. Got to FLL, met my luggage, went straight to the ladies room near the carousels and loaded one mag, loaded the gun, put it in my purse and away I headed for the rental cars.
Lovely week in Florida -- great weather, good sales trip, good time with friends. Tried to 'check in' the night before, when Delta emailed me -- but the site wouldn't let me check-in online; said I had to check-in at the counter. (okay.) Drove back up from Key West the day of my flight home, got into the area early, so thought I'd try to get an earlier flight home. Got to the counter, asked for the red tag, we filled it out -- and there were two suits and what appeared to an airline baggage handler? They were standing at my check-in spot (on the inside), discussing tags and rerouting and so on, and apparently they were running a test because lots of bags were being tagged out front with the bar codes this way or that and so they were being sent to some space back there where they had to be hand-routed and so on.
Each time they moved to touch my (firearm-carrying) bag, I would bark "DON'T send that back yet!", the woman checking me in would say 'we're not done yet' to stop them from doing anything, and so on... They had some other tag that was apparently going to automatically route the bag for this test or whatever and I finally said: "hey look guys -- how 'bout you go find some OTHER bag to run this test with, instead of mine with a checked firearm! You know? Cause if this gets lost or misrouted, it's gonna involved the TSA and the ATF and the police and god knows who else!" (Thanks and a tip of my metaphorical hat to whoever it was here who mentioned (the threat of) 'getting the ATF involved' when a firearm-carrying bag did not show up at the carousel!)
'Oh,' they said, "it's not gonna get lost or anything; it'll just get routed a different way to the plane." In between all this I asked the woman if there were a seat on an earlier flight (I screwed up and was nearly 5 hours early!) she looked, and the way she said it made me think she was just not wanting to mess with these testing-guys... she said no. (sigh) Should have asked first thing... but I was ... off-plan by arriving so early. (I even forgot to refill the car! The nice Alamo guy, when I said I needed to drive back out -- because I knew they'd charge me, like, $5 a gallon, dropped the gas charge from $25 to $10; just to get me out of the car! (wink)) So, with ill-grace, I accepted that they were going to mess with my bag and so they stuck the extra tag on it and dropped it onto the belt...
Five hours later, the Delta metal arrived nearly a half-hour late (bad weather up north) and when we finally got underway, we managed to get to ATL only about 10 minutes late -- and then sat waiting for a gate for nearly a half hour more... Still, my bag showed up immediately on the carousel in ATL, I again made a trip to the rest room where I reloaded my equipment, and I was on my way home.
I VERY much appreciate all-y'all's willingness to help me figure out the best way to do this. I STILL hate the TSA 'security theater' -- oh and my luck! I refuse to be irradiated, so I got my first taste of a REAL groping. (Holy mother of god!!) I suppose I got an extra careful going-over (sheesh!) because they pulled both of my carry-ons for hand inspection. The 'under the seat' one because I missed removing a bottle of water (dumped three, missed one); and the larger one because the boxes of fudge looked bad on the x-ray. (I brought home 17 quarter-pounds chunks as gifts for my cul-de-sac neighbors for being such wonderful folks, always looking out for me since my husband died.) As the guy opened the fudge boxes (they were very nice about keeping me and my bags together; and letting me watch everything they did -- partly while the lady was groping me!), he breathed deeply and said wow! (It's great fudge; from Key West! The 'barn' where the Conch Train begins it tours...)
Anyway. Successful trip. Absolutely wanted to be (and glad I was!) armed while wandering around Florida, since I did not know good areas from bad areas! (And apparently got to visit some of each!) The convertible was great -- although I am now 100% convinced I do not want one of my own -- when the top is down, there's about 1-foot of trunk space left! I had to seat-belt the two carry-ons in the backseat, which did not make me feel especially secure about stopping anywhere! And I did manage the 5-6 hour drive down to Key West and the same back to Fort Lauderdale with the top down withOUT getting sunburned!! (SPF50, long-sleeve shirt, hat with brim...)