Picture attached: Many years ago the little drive tab broke off so I got a replacement drive. The original drive was stamped 20/10 while the new drive was stamped 23/11. The different ratio made the bike a little faster but my gas milage dropped

. I lived with it like that for a long time. Now that I'm refreshing the bike I thought i could dismantle the drives and put the new tab onto the original drive. When I took the original drive apart I found the original ring gear all chewed up which is most likely what caused the tab to break in the first place. Would like to just replace it all with a new, correctly geared drive.