Was there in fact a "lightweight" model as Mr. Garcia
> describes ?
I bought my first Cinelli in Italy in 1959 and I had never seen a Cinelli with milled/slotted bb as you suggest. Very many of my friends and clubmates rode Cinelli's so I got to see quite a few.
When I lived in Italy a couple of years later, I had a Cinelli road bike and track bike made for me both of which had lighter than standard head tubes, top tubes, and seat stays but even so, the bb's were the standard ones.
Among the very many Cinelli's that I've refinished over the years, I can't recall one with a slotted bb (and this would have been a big surprise to me).
I can't say it never happened, but it seems much more likely that someone besides the factory modified the bb (as many riders in the '70's seemed to like to do) and then refinished a frame with this feature.
I wouldn't worry about having to revamp your registery.
Hugh Enox