Ok so I need some help from you guys!

The winding stem broke on my 1942 12.68z sei tacche, and the crown was lost!

I’ve run into an unpredicted problem trying to get a replacement crown. The watch case tube is big, ~3.1mm, so it’s too big for a 1950’s sei tacche crown for example, whose case tube is significantly smaller, even though both have similar case diameters and large external crown sizes.

Anyone here have experience with this problem? Anyone know what Longines models will have a crown that fits this size tube? I’m willing to buy a donor sei tacche if I know the crown will fit.


Thanks,
Eric

 

let's tag @ulackfocus

 

That's a bit early for me. The majority of my Longines watches, and therefore parts, were from the mid 50's on.

 

I did not know there could be an issue such as this with 12.68 crowns, but I have indeed learned over time that 1940s Longines calibers had multiple variants.
For example an 8.68 caliber can have several types of balances, several lengths of balance staffs, the balances can have triangular stubs or rounded stubs and so forth. Drives my watchmaker crazy, he says Longines kept modifying its calibers.
It sounds like what you're experiencing.
My best suggestion would be to try and get a donor with a serial number close to yours, and where the movement looks like it has similar finishes.

 

Thanks for the tip, didn’t think to look for a similar serial number, makes sense. Will keep the search alive!

 

Have you asked your watchmaker to source the crown for you?

 

Yes, the watch is in his possession now, I sent him original pics too, hopefully he has better luck than I’ve had.

 

My guys are part of a parts network. They've been pretty successful with Longines and UG parts. Struck out with a Mido crown,

 

Uh oh - there's more "sourcing" happening! "Sourcing" is expensive. I prefer "finding" because it's much cheaper.

 

Procurement Speak...

 

Good news, my watchmaker has “found” a crown, he says it’s a perfect match! Will update once I get it back.

 

Pretty happy with how this turned out, it's period correct and fits the big case tube like a charm. Many thanks to Father Time in Chicago for making this happen.





Below is the broken stem on the left that led to all this drama. The right is a spare fresh stem for comparison. Understandably, the newly installed stem has a fantastic action to it, a lovely wind.

 

I should also point out that the crown isn’t a 100% match, albeit very close, so if anyone does happen to find a 40’s jumbo crown that can fit a 3.1mm tube, I’d be happy to buy.

 

Lovely watch. Dibs!
And that crown looks like a very decent replacement indeed.

 

Thank you sir! Duly noted.