I think it was common practice that bikes were re-decaled or re-labeled for racing purposes, but this is one issue while the labeling of a bike to make it appear as somethimg else is entirely different When looking at questionable bikes, there are several points that I use. Has the bike been professionally painted / re-painted? Are the decals applied as they would be if done professionally? Is the bike of somewhat similar quality as the bike it pretends to be. Are the components of any value if the bike is fake?
Ebay throws another variable into the equation as the seller may have come by the bike through auction, estate sale or otherwise, long removed from the original owner and may innocently believe the bike to be what it's labeled as. You can usually find out by contacting the seller and asking questions. This will usually cause an honest but naive seller to do more research.
To buy such a bike, you should be extremely cautious or aware of what you may be purchasing. Since I can refinish a bike to my own satisfaction, I may buy such a bike knowing that it's a fake simply because I like the geometry or lug details, etc., especially if the price is right. I purchased a 70's Windsor at a local flea market that had been re-labeled "Cinelli". It's not a Cinelli, but I didn't purchase it thinking it was. It's my size, I enjoy riding it, and the price was just right.
Fred Durrette
Summerville, SC
USA