Is this a Mercier 300?
 

So i was talking to this guy and he has tons of vintage bikes, and this one stand out, looks like a 300 because it has 531 sticker, but i do not see any sticker in the forks, simplex prestige shifters, any mercier experts in the house?
Maybe a late 70's mercier 300, help me out!

That looks like either a mixed tubeset or plain gauge 531 sticker -- can you quote the writing on it?

The seat post diameter will tell you whether it is double-butted 531 (26.4mm for a French bike with 28.0mm OD seat tube) or plain gauge (about 25.8mm).

I wonder if Mercier made a model between the 300 and the 100, i.e., perhaps something comparable to the Peugeot PR/PKN-10.

Quote the writing on what?
If it is a 200 i cant be a 531 right?

I think that's a 3 main tubes 531 sticker. Likely in French, so it should say "3 Tubes Renforces" along the bottom IIRC

"that's a 3 main tubes 531 sticker." which is the definition of a model 200, IIRC. A model 300 would be all-tubes/stays Reynolds 531DB throughout

Note poster location in Lusitania. Euro models may differ from the ones we are familiar with in North America.

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Looks like a Peugeot PR-10/PKN-10 equivalent -- not a bad frame at all!

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This mount exhibits some similarities although evidently not 531 tubing:

https://www.flickr.com/photos/kickmy...57651560491580

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