What's one of these then?

[Stingray Matt]

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=4713&item=3753858786&rd=1

 

[Rod Trussbroken]

.

 

[LeftyLB]

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=4713&item=3753858786&rd=1

You would need to make sure that the piece of foam supporting the shorter body horn is transferrable otherwise your left-handed bass won't fit - I think?