The movement appears to be a Landeron cal 39. I am not aware that Heuer ever used this movement in any of their chronographs. Could be a fake.
You will need more collaboration to confirm that this is a real Heuer. Craig

: Also.. have a mooch around the older catalogues here:
: http://onthedash.com/Guide/_Catalogs/

: ..and the OTD photo library here:
: http://www.onthedash.com/Guide/_Chronographs//

: As for the 'clean-ness' of it.. perfectly possible, but looking
: into whether the dial has been cleaned up etc is impossible from
: your pics, they're quite small!
: There are others on this forum who have way more specialised
: knowledge of this era than me.. so hopefully they can offer more
: info.
: Posting up some high-res images will help loads.

: Stewart
: - Heuerville