I do recall, on another piping list, someone mentioning using a length of (wide) plastic drainpipe with a strap riveted on for carrying purposes (the ends being made from drainpipe "end bits" they use to seal off a pipe - the unused end being stuck with the solvent.. Of course, quite waterproof but one would have to ensure the bellows fitted in as well..
Colin Hill. That recommendation came from me and referred to cases for GHB practice chanters. I have made numerous cases for wind instruments out of drainpipe and have always found them extremely strong and convenient, not to mention very cheap. (I've even made them for cornetti - you can bend the drainpipe with boiling water.) They also have the advantage of not advertising the fact that they contain a valuable nickable instrument. I don't know if you can easily find a size that would accommodate bellows. The trouble is that the bigger the diameter, the greater the length you have to buy. At that diameter, you might need to buy thirty feet! Cheers, Paul Gretton To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html