i have been riding this bike for a year and everyone keeps asking me the question, and seems to have a different opinion of what the frame should be ("definitely japanese!", "italian", "spanish!"), but i can't answer for sure what it is... here is a photo of the frameset when i picked it up. note the mix of lugs and no lugs.
i was told that the frame is a custom frame made by the framemaker who used to do frames for de bernardi (name of this person?) and the steel would be columbus brain (which, if true, might help identify or date...)