daderaz
·Really interesting. Do you have any documents to consult?
This is the history of Reverso.
From 1931-33 they used Tavannes movement.
Only in 1933 LeCoultre & Cie developed its in-house movement cal.11’’’U and 11’’’UO (small seconds)
https://italianwatchspotter.com/jaeger-lecoultre-reverso-history/?lang=en