Thanks for the part number Paul. I thought I had lost the screw so was just evaluating the situation. Tried various sources including OPC and it would have taken 2-3 days. Your friendly engine builder kindly saved the day with his magnetic rod and fished it out, so now I can say my engine has been breathed upon by Nick Fulljames!
I like your thinking and a very cheap way to do it :floor:
Pleased you're sorted.
Cheers,
Paul