I use a pelican case model 1150 in yellow with two locks keyed the same (not a TSA key) for my G27 that has survived several flights. I wrap a bike cable (with a loop on each end) through the luggage frame. My luggage has holes in the fabric where the straps go through to the frame so I can feed the straps and the cable through them and around the frame and lock it to the case with the padlocks.
It is not mandatory to use a cable per the rules, but figure it might help keep the case and luggage from getting separated if the luggage was opened - no matter how that happened.
Imagine they have a size that will work for your piece, too.