If you scroll through all the info below you might find a match. There is a lot to read there! http://omega-constellation-collectors.blogspot.com/
I acquired these two recently. Left seems original, what about right? They came from Japan along with a watch on a 30 marked 1037 bracelet. It seemed like a barn find situation but definitely possible a fake found it’s way in. I’ve managed to accumulate quite a few buckles and straps now so will post them at some point.
Acquired the same 14 mm steel buckle last summer from Watchadoo on eBay. I believe it's authentic, but would also like to hear from the experts. Art
Incredible depth of the collection. Kudos. I recently bought this buckle on the bay. Did not see it in your photos. What do you think?
It is not legit. First and easy giveaway: "ACIER INOX" means "stainless steel" and this buckle is gold plated Second: Look at the "molten" appearance of the Ω symbol. That soft shape shouts "fake".
The generic-looking buckle without symbol. Logo buckles weren't prevalent to the later 50s and that also varied by country of sale. Tom
Always a headache to me when it comes to buckles. According to OP, this one look like an original gold plated MG, is it? Thanks guys!