This 70’s creation looks close to unused and I doubt it’s ever been opened before. This is a late 70’s diving chronograph with a depth meter built in the crystal. This works where there is a red marker inside a tube in the crystal, the opening of this tube is blocked by the water, and the air inside is trapped. When you dive deeper the air in the tube compresses and the water comes in pushing the red marker indicating the depth on the bezel. This is a Longines product, but I suspect some cheeky dealer in the 70’s had some made and sold in France.
The case back is seriously hard to open and the nut glue option looks the most promising!
First attempt fails… I glue it on again and leave it over night.
Next day I finally get to see the movement. Valjoux 7733 is a great workhorse and this movement has never been touched since it was first put into the case. They went to the length of marking the bridge Longines.
Very funky dial in perfect condition.
setting/winding mechanism.
I start taking the movement apart. Even though it looks clean there are small particles of dried oil and grease.
The 7733 is a very nice movement to work on.
Here you can see the basic gear train layout
Even the old mainspring looks like new.
I have cleaned the movement and put the shock jewels back in place to see the balance swings freely.
I then fit the gear train in the base movement.
I fit the winding/setting mechanism.
I now put the rest of the chronograph together.
Robust Valjoux 7733 preforms like the day it was new.
Movement ready for dial and hands.
Like new.
Movement back in the case looking great.
Crystal gets a light polish and the watch looks great!
