Are the bellows you mention square? I need bellows that are around 2.5x2.5 - 3x3 inches with reasonable extension (haven't figured out exactly how long yet).I have one here. It wouldn't be worth posting the whole body to you but if I can work out how to remove them, I could send the inner bellows to you.
Since I'm pretty specific about the size and dimensions I need, I'll probably just end up making a set. I'll go either the Gaffers tape route or maybe put a little more effort into it and do as Ian has sugested.