Perriand stool, genuine or fake ?  

I can tell you there are a...
I can tell you there are a LOT of fakes out there. Some are very convincing, some are clearly new with faked antique finishes.

Thanks Krenit
Thanks your reply, I am wondering if there any clues to identify these stools?

pics don't seem to show, your link doesn't work
too.
use a direct link for posting photos in your message.

About the pics
I did copy the pictures' addresses in the associated web images, but they're not showing, so I just copied and pasted the URLs. Any suggestions on what to do to show pictures? thank.

maybe try another service
like photobucket? I use that one and experience
no problems.
I've noticed you have to have an account with picasa,
when you want to view other's pictures, maybe that's
the problem when you link to this forum.

ha
I thought the seat or surface was more hollow in these designs?
This one seems flat.
A nice piece nonetheless

Doesn't seem right to me.
The shape of the legs don't seem quite right to me, as they don't seem to taper evenly. The curve around the edge of the seat also doesn't look like it should. This piece doesn't strike me as being genuine.