Longines Tre Tacche 35mm

BlueHands

First of all you have there a great looking watch with this black dial. But so far I study your photos it doesn't look as a flat dial to me more a convex one. If I compare my tre tacche (small size) with my sei tacche there is a difference between those two - so my tre tacche dial is also flat. And all the other authentic tre tacches I saw and found in net have the same flat dials. As @DirtyDozen12 explained, there world is full of watches put together with different parts of different decades. So you should be highly bewared of what you spend to a expensive tre tacche watch, maybe it is not what it seems.

DirtyDozen12

Thank you very much for sharing those great photos of the dial, and for sharing the serial number of the movement. The dial appears to be convex. Apart from the curvature, I believe that there are some subtle but important differences between your dial and the "correct" ones that you posted. Before addressing the differences, I will say that I am skeptical about the two examples (first two photos are of the same watch) below. These dials are certainly similar to yours, but I think that they could have come from sei tacches.

Moving onto the "more likely to be correct" ones, the key difference is the sub-dial design, IMO. The first two examples (first two photos are of the same watch), have an "old" style of font that is prevalent on tre tacche dials. The next dial looks like those found in "DH" Longines from the early 1940s. [As a side note, I have also seen "DH" examples with the first dial below so it would be prudent to inquire with Longines before buying.] This sub-dial design is also prevalent on tre tacche dials. The last dial below is difficult to see, but the sub-dial appears to have a "railroad track" scale. In general, this type of scale is more indicative of a tre tacche dial than a sei tacche dial.

DirtyDozen12

Below are two examples of tre tacche dials out of their cases. To me, both appear flat, but I admit that it is difficult to discern.

Photos from: https://watchcharts.com/listing/264...e-12-68z-32-5mm-tretacche-sector-calatrava-3t

Photos from: https://omegaforums.net/threads/longines-21441-tre-tacche.65030/

Yes, it is my contention that the tre tacches one sees with "your" sub-dial are likely the products of dial swapping. I am happy to be proven wrong.

Below are two 35 mm tre tacches (ref. 3864) with the same order number (21'764). The first one (case number 159) has a dial that is in the correct style, IMO. The second one (case number 163) has dial that is commonly found in sei tacches. It is difficult to see the flatness/curvature of each dial, but I thought I would post them anyway.

Photo from: https://www.horare.com/products/1940s-longines-tre-tacche-35mm-black

Photo from: https://www.bloomberg.com/news/arti...-find-longines-gilt-dial-tre-tacche-calatrava

DirtyDozen12

Below is a comparison of your black sei tacche dial (convex) and a black dial from a ref. 5707 (flat). I have added a red arrow to each image to indicate the estimated direction of the light source. On your dial, this is evident from the difference in tone between the outer edge and inside the minute track. On the 5707 dial, this is evident by the small shadow opposite the red arrow. In contrast to your dial, the tone of the outer edge looks essentially the same as the tone inside the minute track.

Photo from: https://www.ebay.com/itm/194458579334?hash=item2d46a27186:g:5DoAAOSwPRJhcwET&nma=true&si=%2BQP%2F7deIqwSiAlQ7xmFxpeShBpQ%3D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

hejsam

Yes its easy to see the difference in this comparison. But I find it way harder to see the difference on a glossy black dial like mine rather than this matte black dial and especially when they are in a case and the crystal makes its delusions.

Again, thank you for all your help. I will have my eyes open for a correct flat donor dial but with pretty small hopes and in the meantime wear this with joy, and since I found out many of the 35mm tre tacches already is not what they seem this makes me less anxious to actually find a correct dial! 😀

DirtyDozen12

Another glossy black dial. This one is from a sei tacche and appears to be flat. While I am skeptical of convex tre tacche dials, there are are certainly flat sei tacche dials that are original.