I am fairly sure that it is an '82 model frame and still has the '82 style airbox. The frame may have been modified to move the frame tube, that runs between the top shock mounts, out of the way of the top of the single shock. Maybe this is why the stock sidepanels don't fit anymore ? Bit of a shame really. His excuse for the vandalism is that it gives a better ride
. An '83 CR500 would have a frame number of CO-1xxx.