16 years is a long time to set, clutch disc could have bonded to rust on both flywheel and pressure plate, now that it is back into service it is likely just quickly eroding the disc fiber surface away. Rust on the nose of the input shaft where it goes into the pilot bearing could be behaving the same way. Disc hub could also be hanging up on rusted input shaft splines.
If it was adjusted away and is now back a month later, something is wearing fast or dragging/smearing/galling. Sounds like you will have to pony up for a new clutch.