Just thinking, can't imagine it'd be all that much work/expense to make your own custom case. Think you can get a huge sheet of 9mm MDF from B&Q for about a tenner. Can't cost that much for a load of thick foam. Also, 2 square metres of cheap velvety material (bought for Little Bear's Red Riding Hood Costume) came to £6.50. Some paint or plastic material for the outside. Add some hardware for around £20 odd quid and you could get a pretty spot on case exactly to your specs for about £60 all in.
The only problem is the labour which is always my sticking point. I'm seriously tempted to build my own case when I buy my new bass couple of weeks. I may do a build thread on it. Thing is, it's a really big if; I do get ideas and then apathy sets in quick. Mind you, I'm sure there's a load of things I may be missing here as well.