When I lost the original button, I also put a nice big hole (well big compared to the size of the shaft that has to go through it!) that needed to be patched before a new button could be put in.
My method: just some scrap denim fabric, folded over to cover both sides and sewn on with a zig zag stitch.
Next I button everything up to find where I need to place my new button, drive the nail through the fabric and hammer it in!
Gardening Overalls ready…now if the rain would stop for the next few days I'll be able to move the 14 yard of mulch that are sitting in my driveway....