I am rebuilding a larger pump pneumatic and one of the bellows had
some pretty serious damage to it and I will have to build a new one.
It's not a big deal, really, but I am having a heck of a time finding
the right thickness of hardwood plywood.

My question to you all is why did the factory use plywood in the first
place?  I can take a piece of maple or poplar and plane it to the exact
thickness I need so why wouldn't they?  I think it was simply a cost
issue and nothing more but want your take on it before I make one my
way and end up maybe having to redo it.

Joseph Musser