Hi Nicolas
Have opened the case. This appears to confirm stainless steel. Stamped on the back is "Acier Inoxydable". Le Coutre Co. The number 1116847. A scratched on number is 905 or 405 R77. Swiss Made. Compressor. Brevet. Suisse. 1 - 68. E859.
On the case near the balance wheel is the number 1952228. On the movement is "Swiss. Fab Suisse. Jaeger Le Coutre".
As soon as I can get photos will upload them, however the site photo uploader is reluctant to load on my PC.
Thanks for your help
Kind Regards
Cookerman