Hi there! I flew my dress with my to the UK for our wedding and then back to the US for our US ceremony. The dress was my mother's so there was no way I was letting it out of my sight. I put it into a nice travel bag (the lady who did the alterations gave it to be so it was professional quality) and folded it into my carry-on. It only just fit (cathedral-length train, woot woot!). I packed the acid-free archival paper from its storage box in the bag with the dress for travel.
I did not have the airlines hang it or anything- the stewardess told me that they can't really do that anymore but that may have just been because the plane from my home airport to Detroit is teeny tiny. I took it out and rehung it as soon as we got home. You could tell it had traveled but I had it ironed before the big day. I flew my undergarments (crinoline, etc) in my checked bag because, while not ideal, they could be replaced.
Did the exact same the other way with no problems, as well. There was a terrifying moment going through security in our connecting US airport where they kept running the bag containing the dress through the scanner over and over again. I was dreading having to ask to go someplace a little more convenient if they needed to search the bag but they let it through in the end!
Loving both our your flowers. I would do that but think I might cry if I did that to a book. And I am nowhere near crafty enough to make them look *that* good, Lyonaria.