Ok thanks all, panic over.......don't panic Mr. Mannering
I picked up a Presto HSS bit at local store' they had cobalt but not the size I needed
I grinded the remaining heads down.
Got some plastercine, dammed around the rivet and poured in the best heat conducting oil i know........extra virgin olive oil
drilling wasn't too bad, a lot of swarf, the rivets were at least 15mm depth in the core
heavy duty, but why stainless steel.
We all know economists build cars these days, even an extra component costing a few pence more is a no no.
Those SS parts would have been better placed in the window cables LOL
The aftermarket ball joint comes complete with 3 X M1O bolts, washers and nylon nuts, at £17 that's a good price.
iirc the complete arm and ball joint is £250ish