In my conversation with the seller, he asserted the bracelet was genuine Gay Freres, though it a) is not a fliplock and b) clasp is not marked. I've never come across a genuine Gay Freres bracelet that wasn't marked as such - while I'm not entirely certain that was always the case, I do know that the market values the economy "Gay Freres-style" BOR bracelets that came on Viceroys and many of the non-automatic 1970s Autavias and Carreras significantly less than the real article.
FWIW between the replaced hands and the non-high-quality bracelet, I would pass on this unless it was cheap enough to use for parts / bracelet was correctly valued.