Hi mr. davis and Mod CJ,
Yes the machine you have is a Model 45 and everything bar the handle bar is pretty much the same as a regular Gull Winged Scotty.
This is a "Dual Aluminium plated chassis" which would date it around 1974, and thus it should have a 2 HP "60102" Briggs engine fitted to it while all the normal Scott Bonnar designated machines still had Kirby 2.5 and 3 HP engines fitted at this point in time. (HK25~H4 and HK30's)
The Lawn Kings were a store brand machine and were priced lower to sell thus they had lower powered engines fitted and cheaper handle bars fitted. This was the only differences between the two variants.
Cheers,
BB.