I'm looking at the 1960 Herse Fédéral in BQ #27 (Spring '09), frame is a good match except for a cable-operated F. der., and Speedy tubing rather than Vitus.
As I understand it, a Fédéral wouldn't normally have the Herse cranks (and special BB) or stem, so maybe this one was upgraded before it left the atelier (buyer ticked all the extra-cost options boxes), or maybe the hi-zoot goodies were put on later.
What I don't know is whether there was a Fédéral model in '51. Or could there have been a mid-priced model between the Fédéral and the top o' the line?
Of course we're just taking the seller's word for it that this is a '51, but it seems reasonable. Can one tell by the serial number? Someone should ask Heine, though I think I have exhausted my interest in this particular bike. If I'm boring myself, I know most everyone else dropped off long ago!
Mark B