Hi Darryl and thanks guys for your responses. I had another crack at the alignment yesterday with the assistance of a panel beater (!!) and we were unable to get it any closer despite changing out the loose pivot bolt holding the adjusting bolt in the bed knife body arm.It firmed up nicely.

I see what you are getting at with the bar but wonder how you "run" the bar along the bedknife and the rollers. Is the mower suspended and/or upside down and/or just sliding the whole machine along it in standard position? I guess the other question is that if the blade is only out by the proverbial bees wilbur how can you tell with your bar and nut?

I had another thought and wonder whether its possible to sharpen the blade to the incorrect rotation. (ie back to front and what impact that might have). Darryl what side is the sprocket on the Scotty's on as you face the mower from the front. The Alroh drive is on the right as you look from the front of the machine. I wonder if anyone knows whether its possible this is the problem. The sharpener did not ask and thinking about it there is no way you could tell.

Thanks again guys for all your suggestions