A network for historic guitars and vihuelas
Kingham (MTM) will make a custom case but you will need to provide a drawing. It's certainly not the cheapest option. Alternately search for a parlour guitar case or perhaps a 3/4. Check dimensions first though.
I am making coffin cases that are nicely padded. Check out: http://lehmannstrings.com/ and look in the Early Guitars section. I'll send pictures if you are interested.