You still said some of the parts were high quality/rare when they are in fact, not so. You totally misled the buyer into buying something that was not worth what it really was.

If you were really being fair, you could have worded it like this:

"Up for auction is a pretty average fixed gear conversion with some cheap wheels and tires, and stock parts off the original bike. I don't really know much about Keirin racing, or NJS standards for that matter, but with that being said, I think the bars might be NJS. The cranks may look deceptively rare, but they are in fact not so. Happy bidding!"