Thank you, actually I did that in the first place (before the whole Longines HQ saga).
Found a Sei Tacche, bought it. Looks perfect...but....the outside diameter did not fit. The inside diameter was perfect, as it is the same movement 12.68z indeed, but it was too "thick" for the slot in the watch case. So it seems there were some kind of differences...What would really help is a measurement of a holder from an actual Longines WWW.
Thank you for the hint!
Click to expand...