Bass Direct have one of the standard, German made ones in https://bassdirect.co.uk/bass_guitar_specialists/Sadowsky_Metro_Line_24-Fret_Vintage_J_J_Bass,_Swamp_Ash_Body,_5-String_-_Black_Pearl_High_Polish.html
Found it again
https://www.basschat.co.uk/topic/319377-hard-case-for-fender-mustang/?do=findComment&comment=3466911
https://www.basschat.co.uk/topic/319377-hard-case-for-fender-mustang/?do=findComment&comment=3696989
A Google search I made in the wee small hours, a couple of nights ago, revealed that the Gator XL will fit a Mustang with a tiny bit of forming of the foam, it was a BC thread IIRC.
Using their logic, buying a guitar or bass is a complete lottery. As to hearing a more consistent tone from a particular wood in a band mix, I call snake oil.