scandinavian or american armchair  

That looks rather Norwegian...

@20thld.  I have come across this chair before. It is Brazilian. I think I have images of a stamp somewhere.

This name pops up on Google. Liceu de Artes e Officios. 

You will get some info if you google that

@andersen.You are thinking of the "Holmenkollen chair by Arne Tidemand Ruud.; which is Norwegian.

Thank you very much Lexi!

Indeed that’s the one I was thinking about. I recently saw one in person and I was impressed by the metal system underneath to adjust the angle of the chair. Nothing you would see in a Danish chair. 

@lexi, do you maybe have any info whether this other chair is also Arne Tidemand Ruud ?

@andersen I don't think so. I did a Google search and your chair is apparently by W.D. Andersag. Italian , 1960's. No labels or marks posted by sellers of these chairs.

Adding image of Arne Tidemand-Ruud's 3000 series for future reference.

@lexi you're pretty impressive. I don't have that chair, it popped up on the internet. That's really funny it was manufactured it Italy. That makes little sense to my eyes. Is there any info on who or what W.D. Andersag was ? That sounds more like a scandinavian rather italian name. I guess its who designed it, but not who produced it.

@andersen according to some sellers it is made by "Ideal Piacenza" There is a W.D.Andersag chair with similar design to the Holmenkollen chair by A. Tidemand-Ruud.