I'm in NorthWestern Ontario Lu, not so far from you ion the grand scheme of things.
Has the school in Montreal that had the roll-over operating again yet?
You can be assured that the next chance I get to closely inspect an R22 I will take it, curiosity is running rampant now. I notice you referring heavily to this FAA produced rotary aerodynamics book, have you consulted other publications or are you just pointing out the errors? Government publications have a nasty tendency toward error.
As an aside, one has to take a look at what the aircraft was being used for when assessing wear. A training machine with excessive wear on the rotor head would be expected in my experience. That machine would be doing a high number of autorotations under student control, resulting in regular rotor RPM excursions, rapid throttle recoveries at the bottom, inappropraite control inputs, and hard landings. Any sircraft used for training will take more abuse than one used for other purposes.