A collector friend had these Cinelli headset spacers reproduced. One pair is chrome plated steel and the other pair is silver. This set has been spoken for, but if there is interest, he would do another run of them, as it is quite a costly process, it only makes sense to do if he is having 10 or so reproduced. They are expensive, current cost is about $200 each, but the more that is reproduced in a run, the lower the cost will be. If you have interest, email me and I will get a tally of how many to make and we can go from there.
This spacer was originally included in the 1950s Cinelli headset. At the time, the headset was not liked by mechanics as it required a special pin tool, and was prone to coming out of adjustment. When the Campagnolo headset came out, it was common to discard the Cinelli headset and leave the Cinelli headset spacer with the Campagnolo headset. The early to mid 1960s Cinelli SC we have at the shop has a Cinelli spacer with an early Campagnolo headset. I also noticed in The Competition Bicycle, the 1960s Cinelli featured is equipped with a Campagnolo headset with a Cinelli headset spacer.