I thought there might have been some grease, stopping adhesion, but it was as clean as I had thought I had made it. So I sanded the paint down to the metal to try for a better grip. I kept the original sugru in there, and added more, this time, up to where the screw should be. Before it set (you get 30 minutes’ play) I put the ribbon cover from the other Lettera 32 on to check clearance. It was fine, but I noticed the difference in paint textures.