Originally Posted by
Charles Wahl
I don't think so. Looks like a Prugnat S4 windowed lugset to me, which was used on a lot of bikes made out of all kinds of tubing. Also, the subject frame has a Reynolds 531 decal near the top of the seat tube (1st photo).
Charles Wahl is correct of course. They're nice lugs, if you like the wrapped-and-welded sheetmetal type (and I do), but completely generic, used by probably hundreds of builders.
Seldom seen on Italian bikes, or anything with Columbus really, most often seen with 531.
EDIT: I wrote "wrapped and welded" but I don't know that for sure, they might be bulge-formed, which doesn't involve a weld. There are no visible welds on those Prugnats, but it's possible to make the weld "go away" with post-weld finishing. Here are some Cinelli welded lugs from the '70s, welds mostly smoothed but there are still telltale signs of where the welds are:
(scanned from the old Rivendell Lugs Calendar)