I came accross a C/L ad a few weeks back for a "Centurion 10-speed", asking price of $25. The photo was pretty fuzzy, showing a vintage bike that had a bolted on aero bar. I called on the bike and the owner indicated that it was a Semi Pro. The bike has some history, having been ridden by the first owner in the Iron Man. It was sold to the next owner who had it handing in his garage for years. He later gave it to the person from whom I bought it when he heard that he intended to do a triathlon. That person rode it in an Olympic length triathlon and then stored it, finally listing it on C/L when I bought it.
The bike is almost all original, with only the seat having been replaced. The SN starts with M0K, so I am assuming a 1980 bike. It was REALLY dirty and needing the normal parts replaced. Sorry, no "before" pictures. I completely stripped the bike and repacked all the bearings. I replaced the cables (Jagwire) and housings, brake pads (Jagwire), brake hoods, rewrapped the bars, and added my SPD pedals. I replaced the 90mm SR stem with a Nitto 110mm stem which I polished to better match the bike. I also took an old Avocet Racing saddle and recovered it in undyed leather. All in all, I am very pleased with the bike.
Yes, I paid the asking price, no haggle.