HI Damian,
I feel that the secondary chain (cutter to Land Roll Clutch) is way too tight and this will ad strange noises into the equation.
It's a bit of a fine art to adjust that one and the rear roller chain simultaneously, but for that reason the land roll clutch is adjustable in two planes, up and down while also left and right. I would just loosen the two nuts ever so slightly and then using a pin punch on the top edge and tapping the slider downwards very very lightly this way you'll achieve a slight amount of chain deflection which is all you'll require.
At the moment it is stretched rather tightly and this would be placing a lot of lateral load on the two bearings concerned which is quite unnecessary.
As Jack has allured to that the set on the blades will have a certain sound that will change if the set itself is altered. (Thanks Jack)
Cheers,
BB.
