I purchased a frameset Saturday that doesn't really qualify for our list, but I asked Dale for an exception becuase it is interesting. It's a Serotta "CSI" from the mid-1990s. It is perhaps the last time that a manufacturer invested in dedicated tubing and a special lug set for it. The seat tube is tapered and the bb end is slightly oval. The top tube is oval at one end, and the down tube is tapered. The lugs are really nice, although not thinned in the style of top custom US work. Yup, too many were produced to qualify as "keepers of the flame," but there is a lot that is traditional in them: All steel, fully lugged, one-inch headset and 27.2 seat tube...
What's it remind me of? Well, think about the best production bikes of the 1970s, like the Paramount and the Raleigh Pro. To me, these Serottas honor that history: production bikes built and equipped to a very high standard. But, these late Serottas also remind me of the painstaking work that builders from Rene Herse to Bill Boston did to custom-fabricate lugs for non-standard applications like tandem bottom-bracket tubes.
It's a side path, and I don't think they detract from the recent dedicated lug sets for (slightly) oversized tubes from Richard (no relation) Sachs, Pacenti, and others.
These Serottas aren't particularly rare or expensive, may be worth having as the end of the line, and a nice way to play with other off-topic "stuff." But, since they are not customs and are designed for indexed gear trains, we must not continue this conversation in Dale's garage. I'd love to hear off-line from others (and would share such posts if asked), and appreciate Dale's courtesy in allowing this exception to our usual discipline.