Anybody recognizes that logo?  

Effkå Möbler ?  They were a Swedish company that made modern furniture. 
I know you posted pics of this piece in some other thread here but Googling spelling possiblities was more fun than sifting through threads, so that's what I did.
 
If you want to know-
The first letter has to be E because E is the only letter that has the bottom horizontal part along with the midline horizontal--both of which are faintly visible in your logo.
The last letter is an Å.  If this was a very common Swedish word, it would probably show up in a google search if you just typed an A, but Å is a separate whole letter from A in the Swedish alphabet and on more obscure words you should use it.  Google won't recognize A as a substitute unless it's something commonly searched.  
Next to last letter is a K, obviously.  So all you have to do is type "EAKÅ Möbler" (with quotation marks) in Google and start changing out the second letter as needed until you get to a likely result.  In this case, Google suggested Effkå when I used F, and in looking at your logo again, I see that that makes sense.  
I guess it could be something else but I kinda doubt it.  You can always keep going through the alphabet if you want. 
 

Spanky, you're a machine!
I think Google didn't sent those options yet in Canada.
Honestly I don't know how you came up with all those infos. When I google Effka Mobler I end up with 2 or 3 pictures and no informations whatsoever on the company...
I'd like to know your opinion on reupholstery project. Do you think this piece of furniture is worth throwing 2000$ at it (Kvadrat textile + foam and reupholster fees).
We love the design, the frame is solid and in excellent condition. I am just wondering if this would be a good or a bad investment considering the pretty unknown nature of the company...
Looking forward to hear your thoughts!
Cheers!
Vinc.

I don't have any more information than you do about the company, I merely figured out the most likely interpretation for the faint logo in the single photo that you posted in this thread.  That company made a couple of other pieces of 50s-60s era Scandinavian Modern furniture so it's highly likely that I'm correct.  That's all.  I mean, how many other possibilities are there?
As for value, I have no idea because I still don't even know what the piece looks like.  And even if I did, I have very little idea of the value of things just off the top of my head, though I do think that market value should only be one consideration when trying to decide whether a piece is worth reupholstering.  The other things you mentioned--quality of construction, style, your personal feelings about the piece---are very important too.  

OK, never mind--I am happy to find that the new forum makes it really easy to find other posts by a person, so I found your other thread about this same sofa.  (Still, it's best to just add to an existing thread rather than start a whole new one about the same sofa.  It's just less confusing and then all the information is in one place.)
I still don't have an opinion on whether it's worth redoing, after seeing the whole thing.  Sorry!