This was an estate sale find today and I took a chance on it since it seemed to be well preserved (and even runs with a fair amount of accuracy over the last several hours) but I don't really know much about it so I'm hoping for some pros to enlighten me here. Is this guy somewhat run-of-the mill or anything semi special? I like it just because I like the style and for that alone I'll wear it but if it's worth a fair amount that's something always good to know and inform your future decisions on!

 

I did also notice that the crown says "Mido" which I thought was an entirely different brand of watch. Would that signify that it might have been replaced during a service at some point? As you can see in the pictures the case lug and case back both have 1906 stamped and the case screws seem to be missing.

 

As you correctly identified, this is what many collectors refer to as a sei tacche. Yours is from around 1946, as per the 7-digit serial number on the movement. The "LXW" marking on the balance cock suggests that the watch was originally sold in the USA. All three hands are the correct style. Unfortunately, the dial has been refinished at some point. This hurts the overall value of the watch significantly. As you noted, the crown has been replaced with one from a Mido. The "1906" is an individual case number and the "23,044" is an order number. If you contact Longines with photos and the serial number, they should be able to provide you with the reference number, along with the original date of invoice and some other information. The missing case screws are common

 

I thought the dial looked far too good and the lume far too intact. There is some spotting on the dial but out of curiosity and an attempt to learn, what gives it away as a re-finished dial?

 

The clear giveaways are the signature and the outer scale. Comparing it with original examples is the best way to appreciate the issues. I will find some examples for reference.

 

Would this still be radium lume or would it likely be something newer given the re-work? I can say it will glow under a black light but will almost immediately dissipate much like my ~60's Waltham. That may not really mean anything at all though!

 

Greetings,
It does look quite pleasing despite the refinished dial, but one thing I would suggest is to get that crown replaced and to sell it separately to someone who might need if.
Those nice mushroom shaped crowns are not that easy to find I believe, and it’s got nothing to do on a Longines like this. And it might be super useful for the restoration of a nice Mido watch.

 

I think that if it does not glow at all when exposed to 'regular' light and only glows briefly when exposed to a black light, it could well be radium.

Here are a couple of original dials:

https://omegaforums.net/threads/longines-12l-estate-sale-find.73699/page-2#post-1911588

https://omegaforums.net/threads/longines-12l-estate-sale-find.73699/page-2#post-1911953

 

Good call... of course I'd need to source a correct crown somehow.

Edit: and find someone to put it on as that's probably a little outside my skill set. I can (apparently) replace the lithium cell in a Seiko Kinetic but I'm not sure about diving any further into something, especially this old

 

It will be very difficult for you to source a correct crown, and frankly not really worth your while considering the fact the dial is refinished.
But since the dial isn’t original, having a correct crown is not essential, so long as it works and it looks adequate.

 

Ah ok, understood. Thanks!

 

Hello and welcome to the forum!

Nothing much more to add to what our resident experts have already said. It is a nice looking little watch, despite the redial, so if it works fine, just enjoy it and wear it in good health

Ms @Syrte makes a good point regarding the crown, might be useful to another collector.

 

Any idea what type strap would have come on this originally? It seems very similar to what is commonly called their “military” version, would that mean it had some type canvas strap like say an A-11 or A-17 would?

I’d thought it might look good with that or with a basic leather strap with the stitching right after the lugs like this? https://benchmarkbasics.com/product...MK84xYeDiqcdPVmIZSnRaV6T42xz35QsaAlFoEALw_wcB

 

The original strap would have probably had the following stitching pattern:


https://www.vintagelongines.com/index.html#brochure17

 

Nice, thanks

 

Info came back that it was reference 5540 in stainless steel with caliber 10.68N / 10L and was ordered September 7th, 1945.

The whole experience was worth it simply to see that amazing record keeping at work 77 years after the purchase!

 

The service of Longines is outstanding, providing this information for free.