yes, these pop up relatively frequently and we need to define "authenticity" here.
these watches clearly use authentic Breitling components, but they are not "correct",
i.e. the components do not fit the model they claim to be; you might classify them as
"Frankenwatches" in the narrow sense of the term.
here are the original models we quite often see mixed up in these watches:
ref. 7806 should be a Navitimer, manual wind V7740, date at 4:30
ref. 7806-S should be a Navitimer, manual wind V7740, date at 6
ref. 7808 should be a Chronomat, manual wind V7740, date at 6
ref. 8806 should be a Navitimer, Chrono-Matic Cal. 11/12, date at 4:30
ref. 8806-S should be a Navitimer, Chrono-Matic Cal. 11/12, date at 6
ref. 8808 should be a Chronomat, Chrono-Matic Cal. 11/12, date at 6
your watch clearly is a model 7806, but has an 8808 caseback, so incorrect - both the
function (Navitimer vs. Chronomat) and the movement (manual vs. automatic) do not fit.
now to the question nobody can really answer - were these watches assembled by Breitling,
in a period of immense economical turmoil, just before Willy Breitling was forced to sell off
his last stock of spares and completed watches, machinery, patents, production rights and
brands and finally close down the company, or were they assembled from that stock of spare
parts Willy sold, primarily to Albert Wajs, Helmut Sinn, Lester Harrision and probably others ?
Bill will chime in, afaik he thinks these watches appeared on the market in the early
2000s and were assembled from stock components; I tend to (hesitantly) disagree -
Phil (Saabreit) even spoke to Albert Wajs, who confirmed that (almost) no Breitling-
branded dials were included with the components and the watches were only produced
with Sinn and the O&W "Aviation" logos.
the dials we see on these pieces appear to be correct, mass produced original
Breitling parts, I think that Breitling decided to use up as much of the available
components as possible and assemble complete watches, even if this meant that
Navitimers ended up with Chronomat casebacks.
on a side note - we see almost no correct Chronomat 7808 and 8808 appear on
the market, apparently they just did not sell well; another reason why there might
have been too many cases left lying around and Breitling was forced to reuse them
in the better selling Navitimers ? Speculation only, of course.
maybe you can shed some light on the history of your watch, the case was produced
in 1974, so among the last ones Breitling purchased, do you happen to know when
and where your father bought this watch ?
the watches appear in catalogs from the early 1970s, apparently launched a bit later
as the "big case" Navitimers and Chronomats, they do not appear in the big 1969
catalog where the new Chrono-Matic models are displayed for the first time.
Here are the known (to me) relevant catalogs:
Navitimer 7806/8806



Chronomat 7808/8808:
