Its a great idea Bill, it must be said, but I'm pushing sixty and flightcased boxes (for amateur band usage at any rate) are very much something for my younger self. Also, I don't know what vehicle you use to gig in, but as you'll know flightcases (or roadcases in American) can be a pain when you try to put them in a car. They are always too big, monstrously heavy and have many very hard metal edges and extrusions that can do untold damage to the interior of a car. Hence my idea about a (short) distance rod. I'd need to put an M20 threaded top hat in the lower 15" box, a standard speaker top hat in the bottom of the cab, 250mm rod, job done, very little extra kit required....