Former Marine ATC. I think you would most likely be fine as long as you conducted yourself in a respectful manner. Some of the crap I've seen military personnel wearing off duty is outside the "regulations" as well, but no one says anything.

I've found that most military and former military appreciate the significance of the kilt on a warrior level.

BEEDEE here is involved with the SAMS up in New Bern. Right there is a built in reason for the kilt. Involvement in a veterans organization! There may even be some helpful contacts in that group if you ever do run into any issues.

Semper Fi!