I've been using this site for years for all the good information, but I have a question I can't really find the answer to. I found ms660 for sale on my local Craigslist for $250. I sent the seller an email and am waiting to hear back from them. The saw is in pieces in a box. I bought an ms361 in similar condition a few years ago and that turned out really well for me, I'm hoping this will be the same. Other than a scored piston or cylinder is there anything that would make it not worth buying? How do I tell if any of the parts are fake/knock-off?