I can still recommend the repair, I use my Supermatic regularly and the replacement has held up perfectly. I have the aluminium pulley with O-ring solution. Sanding down the old rubber should be enough to get by in most cases though? I know it's repeated every where, but don't ignore cleaning and oiling this machine, it took a while before dired up grease was flushed out off the worm gear behind the Elnagraf, and it ran much better after I had the bobbin case out and cleaned out a lot of dust.