I, too, would have removed the bubbled chipped paint before the evaporust treatment. At this point though, it still looks good, and just finish the job as recommended above. This is a great example for people who are afraid of buying a steel bike because it will apparently rust away to dust. Your bike is 38 years old and has many years of good life in front of it. I like the bath tub!
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N = '96 Colnago C40, '04 Wilier Alpe D'Huez, '10 Colnago EPS, '85 Merckx Pro, '89 Merckx Century, '86 Tommasini Professional, '04 Teschner Aero FX Pro, '05 Alan Carbon Cross, '86 De Rosa Professional, '95 Gios Compact Pro, '95 Carrera Zeus, ‘81 Masi Gran Criterium, ‘81 Merckx Pro, ‘89 Cinelli Supercorsa, ‘83 Bianchi Specialissima, ‘VO Randonneur, Ritchey Breakaway Steel, Rivendell Rambouillet, Heron Randonneur, ‘92 Ciöcc Columbus EL