Here’s how I made the cork washer I needed for the project Sunbeam gearbox.
1: The original washer has compressed, but a wine bottle cork makes a perfect for a replacement (teeto tallers can get them from wine making shops). Look for smooth ones, coarse grain encourages splits.
2: Ideally a punch should be made from sharpened thin-wall pipe; the taper on this punch will split the cork, but pressing it snugly into this old bush supports it, preventing the stretch.
3: Press and twist the punch to make the cut, then push the cork out to the required depth and part off the ring with a junior hacksaw. The edge of the bush keeps your saw-cut square.
4: Job done, always soak cork washers in boiling water before fitting - it makes the material incredibly squashy and workable. And save the bit cut out of the hole - it might work on a petrol tap!