DeVille 155-007 help

Greetings all.

New member here. I’ve recently acquired a beautiful (to me at least) 70’s era DeVille 155-007 in very good condition. It appears to have been stashed away and rarely worn, which is criminal in my opinion. But their loss is my gain and I’m happy to own this gem. I would like to get the movement number so I can date it more accurately. The problem is I have no idea how to remove the case back on this one.

There does appear to possibly be a metal shim at each end near the integrated bracelet. I’m guessing these are pulled out to remove the case back? There are no other gaps for a case removal tool and it obviously doesn’t screw down being rectangular and all. I’ve tried to show what looks like a shim in the last two photos.
I wish I had some history on the piece that I could share. It was purchased at an auction here in the USofA. Although not a common piece, I’m sitting here staring lovingly into its glittering hands while enjoying a cozy fire and sipping on some fine bourbon. Too much information? Sorry about that. I got a little carried away.

Any thoughts on the case back or even just comments about how spectacular this piece is are very welcome. Negative comments will be met with rapiers at dawn! I’m kidding of course. Or am I? Anywho, thanks for letting me join the family and I look forward to many conversations in the future!

not sure if this gives any insight. Some of the pictures shows the shim as you describe: https://www.ebay.es/itm/203681137645?hash=item2f6c5783ed:g:aCYAAOSwOBxhf6aH

Welcome to the forums! Our rapiers are ready...

Supposedly a 684 drives this. Interestingly I'd always associated the lowercase "automatic" with the 700 series ultra-thin movement, but similar era at least. My esteemed colleagues will no doubt add more.

Hello and welcome.

I guess this is a 684 mvt. the 7XX looks too big to get inside. it's was probably issued in 1973. I love these watches. ENjoy

Thanks! It confirms that the shims do go all the way through.

Nice find, I'm one of the rare lovers of Omega rectangles too, wish they'd made a slim one with date and a quartz, 684 movements are the closest you can get to this dream

My suggestion is not opening it until it needs a service, if the gasket etc. is degraded it starts getting into the movement

Good point on the gasket.