Looking for some advice on size of counter sunk screws to replace the disc rivets on a Ransome's disc as I can only seem to get hold of 10mm thread size and the rivets that come out measure 11mm, I know they would have been imperial size but wondering if anyone has used a slightly smaller size and if they stay tight when done up as I was hoping the counter sinking on the disc will hold it all centrally allong with the axel hub ?