TELAIO FORCELLA TELAIO BICI DA STRADA VINTAGE 57CM DE ROSA COLOMBUS SLX Acciaio Bicicletta Campagnolo
I believe this is size 57cm. Actual Size is: Seat tube 55.5cm Center to Center or 57cm Center to Top with a 55cm center to center top tube, and a 140mm head tube. Serial is 5, very puzzling as that's the only number I could find.