Sideboard France & Son?  

That is by Ib Kofod Larsen, made by Brande Møbelfabrik.

Wow Leif! thank you so much, super fast and effective 😉
now that you told me, I browsed and found this,
https://www.1stdibs.com/furniture/storage-case-pieces/sideboards/jclause...
"This Rare Mid-Century Modern 1950s Teak Buffet often Attributed to Ib Kofod Larsen. We have a matching Petite Credenza with burnished marks indicating J.Clausen&Son, Brande Mobelfabrik, Denmark. "
Do you think this is correct of you have a publication that shows it is Ib Kofod Larsen?
Thank you again!

I have quite a number of different catalogs with these pieces. Two of them show Ib Kofod Larsen as the designer. Two others don't mention designers except in limited circumstances (like Wegner's and Juhl's most famous pieces).
There is a whole range of these pieces made by Brande with the same handles and legs to fill all the different needs for case pieces in a household.
Here is a link to a post about another of these pieces that has links to pages showing the Ib Kofod Larsen design credit:
http://www.designaddict.com/forum/Identification/teak-credenza-designed-...
I know of another catalog (Povl Dinesen) that has a page with exactly this sideboard and shows Ib Kofod Larsen. I don't think that Ønskebo shows this sideboard, just other pieces in the same line.
I am not sure what J. Clausen has to do with the pieces. My suspicion is that he was the owner of Brande. I suppose because his name is on some Brande marks (which are on some pieces) and sellers always want to say who designed something, it came to be repeated that the design is by J. Clausen. Experience reading the marks on Danish Modern furniture would tend to suggest that is wrong as well. But I guess the extra money from assigning a designer, even if it is an unknown designer and incorrect is worth more than the dreaded "generic" tag.
The irony is that the real designer is actually quite good and far more valuable.

On that other thread I said the name is Brande Møbelindustri, not Møbelfabrik.
I just looked at some marks on furniture that say Brande Møbelfabrik. So I guess they changed the name at sometime, or used both interchangeably.

Thank you very much for your help, Leif! very precious informations.