You can always put the washer the other end of the armature. I always add shim washers so that I have about 0.3mm end float movement on the armature.
With regards to the bellows i'm sure the width of the material is one inch, can't remember the length needed at the moment. Trying to replace the material insitu is pretty difficult, in the end I built my own jig to hold the two end plates in a set position which gives more all round space to work the new material on.
