I think I beat you to it (note the revised description before you finished your post). And no you have not overstepped the boundary, rather I appreciate your knowledge. Dennis shared his concerns with me about the dial and I have been researching the matter further over the last hour or so. I believe that there were several iterations of these flyback dials:

• It appears that there were two different fonts for "Longines" a thinner and thicker variety. My example being closer to thicker variety (though slightly less crisp).
• The "Patent" text is more commonly found above the subdial in print; less commonly in script below the "Longines"
• The presence of the red marking at 12 O'Clock has been a feature in about 50-60% of the examples that I have seen (and that themselves were not obvious re-dials)
• Beyond the dial, you will also find that there are several varieties with regards to the hands; there was a thick blue center minute recording hand, as well as a thin center minute recording hand

I will point out my own (recent) concerns about the dial:

• The subseconds hand is correct, and your concerns are well founded as it would be very unusual for the marking not to extend to the edge of the subdial, and past the length of the hand.
• The subseconds scale may be very subtly off center. I have scrutinized this and from some angles is appears off center. From other angles it does not.
• As mentioned above, I believe that the thicker typeface for the "Longines" is consistent with other examples, but it is not as crisp and clean.
• The dial on my example is not marked Swiss (or anything) at 6 O'Clock

There may be other things that come to light too, but this is what I have come up with. Regardless, I think it is reasonable and fair to conclude that the dial is 100% original (the Breguet numerals are impeccable), but it likely represents an earlier redial and is therefore NOT original factory finish or factory paint as I originally put forward in my description.

I do believe that this would be an interesting area for further research, and will happily contribute and be educated as people step forward with more information and vouchsafe references. While I am a knowledgable collector (and recently, dealer), I cannot claim voluminous knowledge with Longines. I will point out too, that I have contacted the Longines Historical Archives with a request on this piece and sent them pictures of the dial, so I look forward to what their record can contribute to the discussion.

 

Revisiting the font for "Longines" I think it is probably more appropriate to divide examples into Serif vs. Non-serifed varieties. I have pulled some images from google image search and other sites, which I will source if available.
First the Serifed examples:
Ebay

(below) Antiquorum

(below) Farfo


(below) Farfo- apparently same watch from 2 angles

 

Now the Non-Serifed examples (which, in this sample of 3 all have red markings at 12 O'Clock)

ebay (Lou's link above)






By comparison with this small sample size, this last example appears suspect.

 

I'll concur on the Farfo watch being a redial. The AQ watch is an original IMO.