Good points! Thinking about it through the haze of beer and cider, we just don't know what these machines have been through. Tearaways using them as field bikes, crashed and smashed, left out in all weathers, abused, etc. I do know for a fact mine was used as a donor machine by a previous owner who may have taken off the good bits. No doubt they'll also have been painted, repainted, sandblasted and enamelled. When I was restoring the bike, I was insistent that anything serviceable be kept and used/refurbished rather than buying new. I wanted to keep the machine as it was, but with everything 'tidied' up. This may partly be responsible for some of the failures I'm having now. At least this way, when I replace, I know I've got everything I can out of that particular component.