There is a Diamondback on Gunbroker auction number 368406747. It is serial number R29003 and it is a .22 2 1/2" barrel. The odd thing is this serial numbers to around 1978 and it has a 1986 or later maroon box. When you look at the label however this thing really looks correct unlike some of the stuff that has been showing up that is not correct. Also as far as I know 2 1/2" .22s were only made from 1969 through 1970. I am seriously wondering if this is a last year production parts cleanup gun. But if it is would the serial number the stamped on the frame and used during that year or would it have a P prefix like a 1986 should. Also check out the royal blue finish. It is really deep unlike what I am accustomed to seeing on Diamondbacks. This is either one very rare guy or the best fake box I have ever seen. As good as it is I am leaning towards it being original. I did leave a question with the seller asking him about a letter and he said he was quite confident everything was correct with it. Check it out and see what you think.