Hi again Mosic, it is relatively easy to spot a late model Scotty 45 from the mower frame (chassis) : This is what to look for.....
(1) Chain Case cover screws run from top to bottom
(2) Plastic end-caps on the front roller
(3) Alloy height adjuster knob (instead of brass)
(4) Plastic knobs on grass deflector adjusters
(5) Aluminium mower ID plate (red and silver)
(6) Twin rail engine mounting deck
(7) For the 20" Scotty...8 blade cylinder reel
It is still handy to know how to read the code on the Briggs...as that will give you the date the engine was manufactured...which will give you the
approximateage of the machine (providing the engine has not been replaced)...It is not possible to pin down an exact date of manufacture of the chassis.

When Rover started manufacturing the Scotty Model 45 as the Rover 45, as far as I know, it was just a change of colours (red and solid bright green) and was just a badge engineering exercise. However, there are some that feel the Scotty has a better build quality and therefore a better buy....I agree with their sentiments.

Hoping this helps,