...and, sadly*, you don't just match A with A on every cog. There was a chart, saved but lost when my computer died a few months ago , which showed which letter went on top of "A" depending on the number of teeth on that cog. The first-generation cogs didn't have gates that created an obvious spiral when assembled correctly so you really needed the chart to make sense of it.....Or not. Perhaps it didn't really matter. But anyway, here's the chart resuscitated by Google, in case anyone needs it. I love Campag 8-speed.

Edit: *"sadly" may be the wrong choice of word -- my bad. The virtue of the first generation system was that a cog could be used in any position that made sense, just by adjusting the clocking of the cog with its neighbour (like an Enigma machine.) You didn't need to find a "26A" cog if it was going to be the largest, and a "26B", say, if it was going to be the somewhere else in the stack.

I've got some 26T cogs. You can have one for the price of postage if you can tell me exactly what 8-speed system you have. This Branford Bike resource page: https://branfordbike.com/new-page-1 discusses the various iterations of 8-speed cassette hubs and how to tell them apart. Fully intact 8-speed cassettes (all 8-speeds were loose cogs) were still available on Ebay last time I checked.


The image has been cut off. Under the bottom side of the triangle it should read "Sprocket already assembled" or something like that.