Looks like a late 40’s / early 50’s era Calibre P449 Teardrop case in solid gold, not sure of the reference specifically but if you search for JLC P449 teardrop you will find plenty
https://sandersonandson.com/52400.shtml
https://www.crownsandchronos.com/product/jaeger-lecoultre-18k-rose-gold-tear-drop-lugs-cal-p449/