I have an old Disney tour suit that I just acquired and it is made of 2.5-3mm pinseal very sturdy and yes cut down. The shins are shortened from the bottom and the thighs are shortened from the top. The ab plate is overly short as is almost every other torso part.
The shoulder bells are not huge as Vern put it but actually just cut down more, so slightly smaller but they do have a nice ROTJ pinch to them. Everything looks to have been cast from a Jedi suit.
I was under the impression that the suits were almost rubbery for the ease of dancing but the one I have certainly isn't. It's painted white on top of the ABS. The bastardized helmet is fiberglass. and has mesh accross the opened up eyes and the tears have been cut out and mesh over holes where you would normally find mic tips......
It's still a nice historic piece for my collection and I will find a use for some of the parts that are missing from the moulds I use to produce my armour. Like the other shin, correct shoulder bells and possibly other parts. I will need to add the lenght of the parts again but at least I don't have to start from scratch and I'll be able to for the first time supply a complet suit with all lefts and rights......