13ZN Chronographs Inquiries and Information.

DirtyDozen12 · Mar 26, 2019

@Seiji I have seen those 13ZN examples before. Both dials are clearly original. Misalignment in isolation is not the problem. The problem is misalignment in conjunction with a silver foot, atypical signature, exceptional condition (with mismatched hands and replacement crown), and an unusually coarse, vertical grain.

Lépine · Mar 27, 2019

Three world experts looked at the watch and said it’s dial is original; Adriano Divadoni, John Goldberger, and the head of the World Heritage Workshop Bernard Portal. Bernard and John held the watch, used microscopes, black UV light, and a geiger counter. Three invitational Longines collectors looked at the watch. One was uncertain, two said print quality was excellent. I am referring to the email I sent to you from AD sometime last year dated around 2015, it's the one with I think an offer was made.

DirtyDozen12 · Mar 27, 2019

I am sure it won't be the last time that I disagree with world experts. If you do get it authenticated by Longines, it would be interesting to see a photo of the back of the dial.

As a side note, a Geiger counter does not provide definitive evidence as Ra can be taken from other dials and re-purposed.

Lépine · Mar 27, 2019

DirtyDozen12
I am sure it won't be the last time that I disagree with world experts. If you do get it authenticated by Longines, it would be interesting to see a photo of the back of the dial.

As a side note, a Geiger counter does not provide definitive evidence as Ra can be taken from other dials and re-purposed.

Yes? But it is hard to age the dial properly. The lumen has aged with the edges of the numbers darker than the middle. Also, the luminous material has shrunk slightly. There are radium burns on the dial that show up after adjusting image contrast on the file. The top edges of the sub dials have corrosion. The dial is clearly old. There is no fluorescent material in the paint or varnish. It did not turn cloudy under UV.

I have to believe that a factory workshop and the head of Longines workshop with the watch in hand with a 50x microscope, black lights, geiger counter, dial database vs anyone looking at flat 2D photos over the Internet , has to have the upper hand.

Radiumpassion · Mar 28, 2019

Interesting font on the subdials @Seiji

Do you have pictures of other 13ZN's with same style?

minutenrohr · Mar 28, 2019

I´m not saying I know the truth. But, looking on my own dials, I´d state that original/untouched dials don´t have this "unusually coarse, vertical grain" but in most cases "standing" numerals in the counters and a smother radium lume - as seen on one of my pics in comparison. The lume on the discussed dial looks like my watchmaker would have applied it - as well as he can. Furthermore the Longines signature is bigger as I would expect it on an early 13ZN dial. No open 6/flat 3s ? Maybe, but here we have an accumulation of dubious ingredients...
rgds - h.u.

Mark020 · Mar 28, 2019

IMHO wonderful and authentic....

Lépine · Mar 28, 2019

minutenrohr
I´m not saying I know the truth. But, looking on my own dials, I´d state that original/untouched dials don´t have this "unusually coarse, vertical grain" but in most cases "standing" numerals in the counters and a smother radium lume - as seen on one of my pics in comparison. The lume on the discussed dial looks like my watchmaker would have applied it - as well as he can. Furthermore the Longines signature is bigger as I would expect it on an early 13ZN dial. No open 6/flat 3s ? Maybe, but here we have an accumulation of dubious ingredients...
rgds - h.u.

With natural lighting or fluorescent lighting you don't see these vertical lines as much. I use a very directional Cree LED 540 lumen flashlight that angled at the watch helps show all details so I don't have to sharpen images using photoshop or retouch colors. This way the ink hight is visible. You can see it isn't computer generated. You can clearly see the yellow color of the varnish too this way.

Lépine · Mar 28, 2019

I don't think my lumen is hand applied any worse than this.

Lépine · Mar 28, 2019

If anyone cares...serial number is 5.46 Million. One of the earliest i have seen on the Internet. Most start from near 5.6 Million.

minutenrohr · Mar 28, 2019

Here comes my one and only "vertical line dial" (at least the lume is applied propperly)...

Lépine · Mar 28, 2019

Radiumpassion
Interesting font on the subdials @Seiji

Do you have pictures of other 13ZN's with same style?

Actually, there are many 13.33z with similar style on the Internet.

Radiumpassion · Mar 28, 2019

Seiji
Actually, there are many 13.33z with similar style on the Internet.

Yes, but not 13ZN? The subdial font looks like early 1930's style IMO

Nevertheless I'm not saying your watch is a redial, I just want to learn more😀

Radiumpassion · Mar 28, 2019

minutenrohr
Here comes my one and only "vertical line dial" (at least the lume is applied propperly)...

Wasn't this also "authenticated" by Longines? Starting too see a pattern here😎

Lépine · Mar 28, 2019

Radiumpassion
Yes, but not 13ZN? The subdial font looks like early 1930's style IMO

Nevertheless I'm not saying your watch is a redial, I just want to learn more😀

It will take me time to find the photos.I am not that organized. But, yes there are a couple of what look like 13zn. Mainly I found that the script style font of the subdials seems to be a carry over from very late 13.33z. Note: my watch has a serial number on the caseback and the serial number is one of the earliest 1936 manufacture that I am aware of. Watch was invoiced in 1937 to Wirth Switzerland. Predates all the earlier monopushers in this thread. I will add movement and caseback photos later. Note: my movement is a little unusual too, it has wide Geneva Strips, is nickel finished, and still in near mint condition movement.

minutenrohr · Mar 28, 2019

Radiumpassion
Wasn't this also "authenticated" by Longines? Starting too see a pattern here😎

Yes - surely it was. As well as this one:

These were my first (and only - unfortunately!) acquisitions concerning 13ZN12. In Germany it´s called "Griff ins Klo" which means "a grab into the crap". I´m not proud about that and it made me realize that it might be usefull to learn some facts about 13ZN dials.

DirtyDozen12 · Mar 28, 2019

Radiumpassion
Yes, but not 13ZN? The subdial font looks like early 1930's style IMO

The 1930s-style sub-dial font is not a problem, in theory. However, the version found on the dial in question is atypical, in my view. I have seen it twice before: once on a much later 13ZN (see page 1 of this thread), and again on a dial that was for sale on eBay (see below).

Seiji
one of the earliest 1936 manufacture that I am aware of

There are quite a few examples on the internet with earlier serial numbers. Study the signatures, sub-dials, signs of wear, and dial feet of these and I think you may find that your dial is not like the others.

minutenrohr · Mar 28, 2019

Yes - I´m absolutely sure.

Lépine · Mar 28, 2019

It's surprising that redials are not printed as well as originals. I will need to ask the dial makers why that happens. Is the equipment that different ? No right? Why are old redials almost always smeared?

minutenrohr · Mar 28, 2019

Seiji
Someone needs to show me how to remove the crown stem from 13zn. Maybe then I can pull off the dial.

Turn the setting lever screw (just a little bit) anticlockwise. Then push it softly an pull the stem.