Sorry Andrew, I completely missed your last - and I visit here twice a day! That material sounds good. It'd be handy to know the name of it, as I could probably get some in Melbourne.
As an update to my first post, I've been very perplexed about the whole theory of bellows making. I can't for the life of me understand how the above process is supposed to produce a square bellows. I decided to unfold the bellows and re-fold it in the opposite direction i.e., instead of folding the longer ribs outward, I folded them inward. With all bellows apparently, if one rib folds outward, the adjacent one folds inward, and so on. So folding in the opposite direction... wait for it... produced a square bellows, on the bottom, but rectangular at the top. It must have been the other way initially, but I didn't notice the geometry of the small end - only that the large end was rectangular.
My conclusion is, that with this method, the only result possible is one end square and the other end rectangular. My next trial will either be to use this method - but - with all dimensions the same, OR try another recipe like that of Smetz.
I'm afraid with all these methods, I find after many readings of each that I have unanswered questions and doubts about the likelihood of success. I think this is a common feeling.