Took a step back and removed the reducer and plug from the pre-heat system as I found that it was using more fuel. I will have to manufacture a some sort of plug that will fit properly.
I have finished an engine stand with large enough wheels to handle the rough floors of my sheds. It is made of about 90% recycled material. Now, I'll buy some decent 12mm bolts for it and also make a temporary clean room so I can strip an engine I have bought from a wrecker.