Just wanted to give an update.
I ended up tracking this part down, in a Briggs and Stratton dealer, only 10km's from where I live, and it only cost $16.
It was a crazy little place in Toowoomba, that looks like it hasnt changed since the 70's, no computers or calculators, everything logged in books and files, but they knew exactly what I was after and had a couple to spare.
If anyone ever has trouble tracking down a Briggs part, I can let you know the number for these people
thanks for the help
Glen