The key marking inside the caseback is a Poinçon de Maître from the city of Geneva and means that the gold case was made by Wenger.
https://vintagewatchstraps.com/swisspdm.php#pdm5
As far as I can make out, the remainder of the etchings are service marks from various watchmakers (unusual though not particularly attractive for one to score the back of the lugs) and one of those encounters has resulted in the crown being replaced. If you look at the caseback carefully and in different light can you see any faint indication of stamped numbers?