"Most vintage frames come from Italy, France, England, Japan and the US, and to a lesser degree Belgium, Holland, Spain, Germany and a few outliers." -- Austria (mostly Steyr-Daimler-Puch and Capo) exported more bikes to the US than any of your four "lesser degree" countries.
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069