So, when Winchester bought out Cooey, most models got a "0" added - Cooey 84 became a Cooey-Winchester 840, for example. I have had a number of Cooey 60 and Cooey 39 - most are not drilled/tapped for side mount - none had the dovetails on top. All the Cooey-Winchester 600 I have worked with, did have the dovetails. I do have a Cooey 60 that has been drilled and tapped - however - not likely by the factory, since a Weaver side base #2 and rings put the scope noticeably over to the right of the barrel - might have worked fine for a bended sheet metal mount like Weaver used to sell - just bend it where you need it?