Hi Domenic,
You could try typing back laping in the search bar at the top of the forum and you will see a lot of topics regarding the issue rather than try to look through the forums.
What we used in the past (many years ago) was use a retangle block of steel and drill holes in it and place a bolt in the centre with nut either side to lock it and then drill two other holes so that a bolt will fit into each side of the sprocket. Not hard to make no welding etc.
Hope that this is of some help to you.