Yep; built about 5 now. All of my weirdly shaped guitars now have a custom case. The shell is dressed 2 x 1 and 4 x 1 with a 3 ply top and bottom, with an acoustic foam insert with the guitar shape cut into it and a thin sheet of foam rubber underneath. Covered the interior with a plush satin - or material of your choice - and the outside with a roll of vinyl bought off the web for pennies. Case hardware is available all over the place but I used an outfit in Brisbane whose name eludes me currently.
Be advised, though, that these are HEAVY cases, not at all light like the alloy or blown plastic ones you can get today! I'd've preferred a Gator with the movable interior blocks but that would have cost a kings ransom when I decided to build these! The internet is your friend; there are loads of case building videos about - find one you like and go nuts!
I cannot remember the total cost, but it certainly wasn't cheap and cheerful - the sheet of ply did two cases, the dressed pine was cheap as chips and the vinyl was the end of a roll; the case hardware wasn't terrifically expensive, either; but there's a good deal of satisfaction in making your own.... :-)