Mark - just the reply I was looking for which helps me to question the logic behind my proposals. Once again keeping the family tree in full view, here is my response to your questions:

:
: The Family tree is as follows:

: Heuer Diving Watches

: - 1000 Series (automatic & Quartz) + (28, 32, 38 & 42mm
: case size)
: - Super Professional (844.006 + 840.006)
: - 980.003 + 980.004 (Day date with crown at 4)
: - 980.023 (1000m Quartz crown at 4)
: - Ladies (981.058 + 982.058 + 983.058 + 983.048)
: - 2000 Series ????????????

: The main thing that strikes me as I look at the table (in the
: latest form I have it) is how many of the watches begin with the
: 980.xxx reference. With the 0 changing occasionally to indicate
: case material as we are familiar with from the 70s references
: for chronographs (0 for steel, 1 for black or olive PVD, 2 for
: pewter PVD and 3 for gold-plated... or black PVD in some cases.
: And in others the 0 doesn't change even though the case material
: has, Black Coral models for instance. Hmmmm, not as consistent
: or as useful a marker as it is in the chronos. Shame.).

Yes, it would be nice if it was consistent but as time went on and obviously the model was proving to be a commercial success, they introduced so many variations that the reference numbers could not cope and the continuity was lost.

: Does 98X.xxx not constitute what comprises a 1000 Series watch
: then? Why have we pulled out the day/dates and the deep dive
: watch into separate families?

Essentially I have ignored the reference numbers and focused on case design to produce the family tree. The case design which makes up the 1000 Series is common to 95% of all the model references. On that basis the day/dates (980.003 & 980.004), the deep dive (980.023) and the other branches have different case design. In doing so I have also adopted the visual element that Jeff alluded to. The 1000 Series case if specific and recognisable and the other branches are all unique and equally recognisable. It’s a bit like the Autavia family with manual screw back and manual snap back branches which have similar dials but different cases.

And does the 983.048 not belong to

I have grouped the 983.048 with the other three "ladies" references for simplicity sake for want of a better reason. The case is unique but then so to are the other three in the group however all three are of similar size and have a PVD finish. Interestingly, the 983.048 case is like a ladies Montreal and the other three are like a ladies Pasadena (later versions found in the recently uploaded and much discussed 1982 Speciality Watch Catalogue.

I like the name deep dive …..

Me too.

Might not be appropriate in the metal, but it feels like a natural grouping to me.

Once again, and in my opinion the natural grouping is by case design not reference number.

: Which brings me to the Ladies family. I know this just comes from
: having these watches left over and trying to find a name for
: them, I guess, but I see lots of other ladies watches on the
: list and those, I presume, will be sitting under the 1000
: series? If these don't fit under the 1000 series as I'm asking
: above, it might be better to cop out and have a
: "Miscellaneous" group with these in rather than
: potentially giving the impression that these 4 are the only
: ladies watches in the range?

Agreed, I used the title for want of a better one. These are the 4 orphans in the group and were obviously experiments in new case design, which as I pointed out above, are quite interesting. I propose a name change to this branch to Miscellaneous Ladies.

: Looking at the spreadsheet, it also strikes me that we have a few
: orphan references (orphan in the sense that they don't conform
: to the same 98N.xxx format). 840 and 844 are the most obvious,
: forming your Super Professional family, but where does that
: leave the other orphan number, 756? This seems to be the ladies
: version of the 844, does it belong to the Super Professional
: family too?

No, these are the first execution of the 1000 Series. 844 automatic 42mm, 8440 quartz 42mm and 756 automatic 28mm case. The rest of the series grew out from these and in fact the 844 evolved through reference numbers 844/2, 844/3 and eventually 844/4 with TAG Heuer dial featured in the 1990 TAG catalogue. So, not orphan but rather grand daddy & mammy. The Super Professional’s (840.006 & 844.006) are unrelated to the 844 and have their own unique case design and therefore their own branch.

By completing this exercise I have convinced myself and hopefully you and anyone else who has taken the time to read this that the family tree with one modification (Miscellaneous Ladies) and the exclusion of the 2000 Series elephant is correct. Let me know if you disagree – I am very open to discussion.
Regards
Paul
www.heuerworld.com