Oh, and I'm not a Motobecane expert by any means, but to the best of my knowledge, that frame should have Vitus tubing of either .9 or 1.0 wall thickness. Any actual dents would have to be pretty severe before they affect structural integrity. Take a look at the indentations on the chainstays. If the dents in the tubes are deeper than the dents in the stays, then you've got a problem. Otherwise, you've got a cosmetic defect.