Thanks again deejay for you help, advice and great videos. It seriously made the whole rebuild a lot easier.
When I took my Scott Bonnar into the shop a few years ago to get sharpened, they said it requires a very high level of expertise to set these mowers up and should not be attempted at home

Certainly proved them wrong!!
I had the laptop in the shed with wifi watching youtube as I went along!! Certainly a novel way to get the job done.
The new engine is a treat. Nothing like having something that starts first pull.
I'm worried about the two clutch retainer bolts that holds it onto the engine output shaft. They are exactly lined up with my head and I keep thinking they are going to fly off and take me out!! I'm gonna have to whip up a guard cover.
Thanks again!