I am also a collector of Scott Bonnar's and have many model 45's. I have 1 with the same handles as this mower, but it is the usual green colour. One other thing I have noticed about mine is it has a manual choke and manual stop, both not hooked up to the throttle cable like all my other briggs engines. From the pics yours seems to be the same setup. Mine is a model 450810, briggs engine a 74 vintage.
