A bit of inside history.
During my brief period (1982) at Falcon Cycles running the frame shop I also had to oversee the closing of the Barton on Humber Elswick factory. Buried deep in the debris I came across 50 or so rather nice, new, Columbus tubed, Italian built, frames that had been abandoned, unpainted and unloved. Fortunately they were in a part of the factory without the leaking roof so I rescued them, got them all painted and they sold in days.
This is without doubt one of these frames
Andy