I am not convinced that the one on ebay is a genuine Heuerdato,
Have a look under clebar onthedash and you find a clebar with exactly the same heuer-leonidas signed movement that the one had on ebay, hence you just need the dial and crown for a three times margin.
As Nick said the finish of the movement looks quite different than the ones sold under Heuerbrand name.
I will raise the questions next time I will meet the european specialist...

http://onthedash.com/Guide/_Chronographs/63.Carrera/c.Carrera_12_Dato/f.Poor_Man's_Dato_12/Clebar_Dato_(White-on-White)/?show=25CleDatoWhtFF.jpg

Cheers

Arno
www.heuerchronographs.com

:
: The numerous Heuer samples that you have seen, and the fact that my
: sample is "triple-signed" with the Clebar name, all
: suggest that the triple-signed Heuers are genuine.

: We have probably taken this discussion about as far as the evidence
: will take us, at least until we can get some information /
: recollections from those who were with the Heuer company, during
: this period. I have forwarded links to our "best
: expert" and we will see what he has to say about the
: "fat lugs".

: Jeff

: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++