Even before the K version, there was a screw mount version: http://www.camera.co.jp/ginza5th/smc15.html
which I believe was based on an even earlier Takumar 19mm/5.0 Shel > [Original Message] > From: William Robb > The A15 is the same design as the K15, which makes it a pretty > old lens formula, possibly as much as 30 years old.

