Opening Lucien Piccard SeaShark Help Needed

[Taro]

I have a Lucien Piccard Seashark that has a loose crown that needs replacing. Don't know where to find one. That's one problem.

Second, I need to service the motion works but for the life of me can't seem to figure out how to get inside! I've tried an exact knife but no luck. Seems pretty stuck on there. Can anyone advise please?

[Watchtime]

Very nice watch from around early 60's. I love it. Possibly this watch has to be entered by taking off the crystal? Normally the edge for opening is around the 5 marker on the back at the lower right lug but according to your last image it can be at the crownposition, it seems there is a kind of gap?

[oldhippy]

From the looks of the back that movement comes out from the front. It will have a two piece stem you need to pull it out, careful with doing this but some can be very stubborn, The way I used to remove these was to have a pair of nippers and pull from behind the button, when this is done you take out the glass and the movement will just drop out. 

[clockboy]

Agree with old hippy it comes out from the front. Is the crystal fitted in its own encasing and it lifts from the front, as many vintages do. If not it will be a split stem and there is a vid on youtube by Mark on how to deal with one of these. 

[Marc]

+1 OH and CB. It looks very much like a front loader.

However, from what I can see in the photos it looks as though rather than remove the crystal from the bezel it might be a matter of removing the bezel from the watch, it looks as though there might be a join line there. If you can post a clear close up  of the side of the case it might be a little clearer.

If this is right then it is not a true one piece case which is slightly odd for a watch marked as "waterproof" and with a model name that quite clearly infers that it can withstand anything that the sea can throw at it. In a true one piece case design the crystal fits directly into the case, which as the name suggests is just a single piece; there are just two elements (case and crystal) to seal.

With the crystal installing into a separate bezel there are three elements (crystal, bezel, and case) to seal.

It could however be that the crystal installs directly to the case and the bezel then is pressed over the crystal to provide compression of the crystal against the case thus enhancing the water resistance. A bit Seiko-esque.

[Chopin]

It is a front loader indeed. There's 2 possibilities as Marc has said. You will either have to remove the crystal or the crystal with the front bezel to which the crystal would be glued.

You can figure out whether it has a bezel + crystal if you'll turn the watch sideways and look for a very small gap/space between the front bezel and the reset of the case.

Also, remember to keep an eye out for the crown. Theoretically that one should be removed first and there should be a certain procedure to do it.

The crown might be able to come out with the whole movement and dial or it may be stopped by another piece of metal belonging to the case itself.