Here are my observations in relation to whether this is a genuinely Greg Lemond's 1989 TDF Bike.
I will begin with a picture of Greg in the 1989 TDF as posted on Bikeradar.
1) It was typical to write the rider's name on the top tube back in 1989, so that the mechanic would setup the bike correctly, and give each rider the correct bike. Where is "G. Lemond" written on the Ebay frame???
2) Notice the seatstays in the above photo are painted red, not Chrome!!!
3) Do an image search of Greg lemond, and you will notice that he rode a San Marco Regal saddle. The rivets of the Regal saddle can be seen shining in the above photo. I'm not sure what saddle is on the Ebay bike, but to me it looks like a Selle Italia Campionissimo, not a Regal.
4) Look at the decal on the seat tube above the Bottechia name. On the Ebay bike I see blue, then red, then black, then a white rectangular box with writing. I assume this is a "World Champ" decal of some sort, to celebrate Greg Lemond's Rainbow Jersey. Now look at seat tube above. I see what appears to be an Italian flag set of stripes, not a "World Champ" sticker. Apart from the fact that a bike team would be unlikely to bother putting a new decal on a bike halfway through a racing season, Greg won the 1989 Tour de France a good 3 months before he became world champion!!!
In addition, the word "Bottechia" seems to be completely absent on the seat tube in the image above.
It aint the same bike.
The seller is either an idiot or a crook. 'Nuff said.