So I finally got to pick up one of my first Scott Bonnar 2-stroke rotaries after a little bit of freedom. I've added the advertisements that I know one of is definitely my mower. The other that says 1973 model is more of a drawing and there are a few small differences like the colour of the catcher and the handelbar are complete different, so it's probably an earlier model. I don't know, I haven't done enough research on Scott Bonnar mowers yet as I've been mainly focused on my early Victa model restorations.