Hi Crispy,
There is a rather simple explanation about this machine and that is that it's not a Rover, infact the ID plate gives it's true identity away as a Scott Bonnar that's been refinished in Rover Red and has had the decals to suit the 17 inch machine fitted, thus why they don't stretch across the full width of the catcher. The handle bars are finished in red opposed to being chrome in appearance.
The 6 blade reel was fitted towards the end of 20 inch production as it was cheaper to manufacture and by this stage the 20 inch machine was no longer taken all that seriously as a top end machine like it was when it came out with the 8 blade unit.
The thickness of the blades was reduced near the beginning of Series II (twin railer) production as the Series I certainly looked far more sturdy in the reel department, but everything along the way was about cutting costs and being competitive in the market.
In saying all of the above, this machine has been conjured together from a number of different parts taken from various other machines.
The three piece rear roller is from a series one or one of the very early Series II machines.
The handle bars "could" also be from a series one but they were fitted on Series II machines fitted with the Kirby engines.
The PTO shaft bearing housing is from an earlier than Rover machine as it still has the oiling hole.
Can't quite see if it still has reel bearing carriers without oiling holes, but does seem to be the case.
Deflector plate has Series I securing thumb knobs.
Engine and Catcher are replacements.
Front Roller frame is now red and not Zinc plated. (Black on Rover Reds)
6 Blade Reel is from what I feel would be a later made machine.
There's probably quite a few other smaller details that I've missed but in saying all this one would have to call this machine a Heinz Breed.
Cheers,
BB.
