It's hard to see in the picture, but it almost looks like it says R75, which were less common than the R80's or R100's, but very similar bikes. Martinjmpr is right on with the age, I'd put it right about 79-83. As for the reliabilty, compared to some newer bikes, perhaps not quite on par, but for their age they are incredibly reliable, and when they do have a problem they are very easy to work on. They still have quite a following, and strong after market support.