I just got a beautiful set of Record brake calipers. Of an era to have a nutted set up, straight bladed QR levers, etc. Now here's my question. These brakes have a small keeper on the lower reach of the barrel adjuster bolt, below the caliper arm. Meant to keep things from falling apart, obviously. These items have a hole that the threaded bolt goes through, and a small tab with a Campagnolo Logo on it. I have never noticed these before, in spite of owning a few pair of NOS brakes.
I asked around a bit and found folks who said that these were perhaps once leather, then some sort of felt. Mine appear to be card board. Further, mine are held secure with tiny O rings, but I believe this latter may have been the idea of the previous owner.
Were all new brakes shipped this way with this keeper? If they were made of different material at different times, is there a time line for the variations? I've owned a couple of dozen sets of similar used brakes, yet never seen these things before. Could they be rare?
Lansing, Mi USA