Well I went to the car club yesterday and asked about heating sprockets to fit them, and they gave me an old deep fryer that was at the car club full of engine oil.
Heated the oil to 250'F and then in went the sprocket. After a few minutes I lined it up, used the old sprocket as a drift and realised I'd misaligned the keyway. Out with the puller to get it off again, I repulled it two more times, before SUCCESS. Then the bearing. Now clean up and go to bed. Chain is on as well.
Hopefully all will go smoothly tomorrow night.
I need to get me a shed though, I am sick of working in a carport, avoiding nature.
John.