bizarre ... serrota has made a lot of bikes in many configurations. I've seen a huffy branded track frame from the olympics that serrota made can't recall year 80's I think. Never heard of cinelli building for serotta. Stranger things could happen. I would tend to look towards the relationship between the tubing Columbus & Cinelli have been somewhat synonymous at points I think. Perhaps the lugset was sourced from columbus and that BB lug happened to stamped cinelli for some reason??? who knows for sure.