Re: rebuilding cartridges, where they recommend using pieces of rubber band: you know when you use rubber bands to hold papers together etc. and then a couple of years later you take them out of the drawer and the band is all gummy and coming apart? I'm not sure what I would use instead of a rubber band, have not given it a lot of thought, but think I would try to find something similar but with longer life. Maybe pieces of some flat rubber drive belt as used on a player of some sort? The compliance of the rubber band is about right; maybe the drive belt would not have enough "give"? Maybe the whole thing is not a problem?
Reece