You are buying a bicycle of unknown manufacture.
Appears to be a custom build using Italian style lugs and a really cool custom seat cluster. The frame also features Campagnolo horizontal dropouts in the rear and Campagnolo drops on the front fork. Frame was at one point in time completely stripped, then primed and given a fairly poor red paint job. There is some minor surface corrosion on the seat tube below the front derailleur, otherwise appears to be in quite good condition. Unfortunately the area where a serial number would have been on the bottom bracket has either been removed or painted over. Campagnolo rear derailleur dates to 1981 and matches both the crank and shifters in vintage, so we imagine the frame was probably from either the very late 1970's or early 1980's.
59cm Seat Tube (center to center)
58cm Top Tube (center to center)
SR Laprade Seatpost
Cinelli 1A Stem (95mm)
Specialized Handlebars (52 cm center to center)
Campagnolo Record Headset
Dia-Compe Brake Levers
Dia-Compe "G" Brake Calipers
Campagnolo Nuovo Record Shifters
Suntour Superbe Front Derailleur
Campagnolo Nuovo Record Rear Derailleur
Campagnolo Nuovo Record Crankset
Campagnolo Nuovo Record Low Flange hubs laced to Mavic MA40 rims (700c Clincher)
6 speed Suntour Freewheel.
Serial # Unknown