I have the same KK case/duffle combo, used it quite a few times from NY to AZ and back but not in 10 years. With airline fees these days it's cheaper to ship a long gun by the USPS now and probably safer...
Mine doesn't require a special tool though, just 2 padlocks as I remember.
Tribal built would seem to point to K&K. I have one, was sold with a duffel that hides the case in the bottom.
Mine is serviceable, and, nothing more. I wouldn't be in a hurry to put any money into it.
Send a photo or two via email, and I'll get them up for you. My email is in my profile.
Best,
Ted