Use new every time saves money and time on trying to refurbish and you can replace with better quality
that would have to be set screws,which arent as good as bolts with a shankOut of interest what size bolts would you stock up on? X50 M8 and x50 M10? Then cut them down to whatever size you need?
Looks like there are quite a few rust removal products. But not sure if they are available in the UK.
I’d better explain.
Take an old phone charger and cut the socket off. Expose the two wires about 30 mm then with the power on dunk them in a glass of water. After a few seconds the negative wire will start to bubble. This one goes on your nut/bolt. The other wire goes on a scrap piece of mild steel. Stick em in water with a spoon full of soda or salt and switch on for an hour or so. Wire brush them.
Watch the vidvinegar does the same...got some Rover P6 bits coming out of tub tomorrow will post pics...
I found this nice antipodean gentleman guide informative.