Happyjack--The one gun is only marked Cooey Mowhawk 22 cal. on the receiver. Info from John Belton's book says the Mowhawk was introduced around 1937-38 and in 1939 it became the model 75. The book also shows that in 1939 it was changed to the hump back design stock. His info isn't really that clear and not for certain how accurate. The model 600 came oiut in 1967 but I'm not sure when the rabbit stock came out. It wasn't made for Sears or Eaton's as it says Cooey on the barrel as opposed to Ranger or Sureshot which were 2 of the popular store brand names. Not to say that it wasn't also made to order for Sears or Eatons etc. with the rabbit stock but ones I have seen say Cooey. Also, just to point out, there was a "rabbit" model produced by Cooey in the late 20's. I have one and mine is a very small boy's rifle that almost looks like a toy "pop gun". It has a very flat stock and no buttplate. Mine is a smooth bore for the .22 bird shot. Although it is called "Rabbit", there is no rabbit design in the stock on it.