The Bass Cases mentioned are shown below....
Attachment 28526
MMB4 in an Artist Bass Case
Attachment 28527
J Bass in a 'Stagg' branded case
Attachment 28528Attachment 28529
Close up of both Bass bodies in the Artist case..... J Bass is around 25 mm too wide whilst MMB4 is snug with a small amount of space to move around in.
Attachment 28530
J Bass is also too long for the Artist case.