I believe they are mid to late 60's model. The earlier 60's Evinrudes are rounder and sleeker. I run a '71 model johnson seagull (Same as evinrude) on my boat which is predominantly the same from 63-74 models. It is a sweet runner, first pull starter - the best engine I've ever used (Used to run a much later model Mariner which was just rubbish and a later model Yamaha which was worse). I also use a '65 Seagul 2.5hp 40+ has a back up - beautiful engine and a bit of fun too - just leaves a trail of oil slick on the water behind you!
Pete.
