I'm looking for a cable stop reducer (I think) to be able to use modern indexed shifting on my '84 Pinarello. The cable stop looks like this:



I moved that bit of springy cable and its ferrule to another bike. The standard ferrules I'd normally use for shift cables just kind of rest against this stop and folds up into the air wildly. I tried to work around this problem using a brake ferrule that has a pointy end that sticks out of the cable stop and it helped, but I'm still getting intermittent sloppy shifting that I suspect is because of this juncture being unstable.

I found an old thread where this was discussed and someone said that you can get ferrules on eBay that are specifically designed to do what I need here. The thread included this picture:



I looked on eBay and I saw a few things that look like this, but it wasn't clear to me which if any was the specific thing I needed.

Can someone help me out here? Thanks!