Landeron 57

Hello Everyone,

It has been a while since I posted although I lurk around and marvel at the beautiful collections. I came across this triple chronograph and was wondering if it could be a Valjoux 72C variant or maybe a Lemania 1100. There is an 1100 on the back of the case. I wasn’t sure if that was coincidence or not. The inside of the movement is not stamped with any maker or numbers. The crown and movement are overwound and I can't Seem to be able to unlock it . Any help from the members would be greatly appreciated on possible maker, care of the watch and possible restoration. I’m guessing this is 1950-60? All the best! Craig

Thanks Dan S! Looks like a Landeron 51. Much appreciated

Thanks, I edited the title in case someone is searching for something similar.

57: 14’’’calendar
59: 13.75’’’ calendar