I am no Schon expert but I have seen lot's of the older Schon cue's that dont seem to be abundent. I have an older one for sale and do not know what model it is and a friend of mine sold one at the DCC last year that I had also never seen another one like. He had talked to Evan Clark and was told that Schon would make a cue to a customer's spec's and therefor there are quit a few out there that are for all practical purpose's "one of a kind ".
Here is the cue I have. It has the same ringwork as your's and I was told by the owner it was a mid 1980's cue. He also said it was made for a tournament and was awarded to the winner as an added bonus. It is not the fanciest Schon out there but I have not seen one exactly like it. It also has micarta ferrule's on the shaft's.