teak sofa thrown away (new photos)  

Local
Local being where ?
It's a big old world 🙂

I don't mean to rain on your parade...
But you're proposing to invest a lot of work into a non-pedigree, cushion-less, not-quite-complete sofa.
Putting it back together will be a good learning experience, if nothing else.

living in courtrai,...
living in courtrai, belgium.
it's indeed a lot of work or money for an anonymous sofa, but i plan to do all of the work myself and have some fabric and leather that would fit it still lying around somewhere.
lately i scored several pieces in teak, i've fallen for the woods charm and durability. found a very nice, sweet desk in a vacant house (photo following soon) i just couldn't let this sofa rot away...

It doesn't look that bad...
It doesn't look that bad judging from the picture. Physical interaction might tell a different story. Seems like a nice moderately stylized sofa. Getting a new back support made shouldn't be too difficult or costly.
Worth it to me...

.
I can understand the urge to restore abused midcentury cast-offs, heaven knows I've adopted my fair share.
If you're hellbent on doing it, you might consider reproducing that missing back-spindle, instead of removing another in the name of symmetry.
Where there's a will (and a Dremel tool), there's a way.

the spindles are curved in a...
the spindles are curved in a sort of s-bend, it seems quite hard to sculpt this..would it be possible to realise this by steam? or is teak to hard to do this sort of work yourself?

How to carve the spindle?
You ever hear the story about the sculptor who, when asked how to carve a statue of a horse said, "I simply chisel away everything that doesn't look like a horse."
In the case of your missing piece, simply whittle away everything that doesn't look like an s-shaped Danish sofa spindle.

😀
(why did i ever ask, o...
😀
(why did i ever ask, o why..)

If
it doesn't seem practical to make a new spindle (and it would never match the others perfectly, for several reasons) then I see no problem with omitting another for symmetry's sake. Maybe I just like cantilevers. . .
More power to you ! And enjoy your project.

can't wait to see the...
can't wait to see the finished result!

Post some images! Have fun wi...
Post some images! Have fun with it!

Reproducing that S bend would be
a highly skilled job. Go for symmetry, OP!

I recently read somewhere...
I recently read somewhere that teak is such a hard wood it dulls the tools of "ordinary" craftsmen, and leaves them lying in a huddled mass in a corner, mumbling to themselves. Or something like that. The article said that because teak is so hard to work with, it requires highly skilled craftspeople. So that might be something to consider.

How difficult or expensive
would it be to take one of the spindles as a reference piece to a local cabinet maker and have him carve, cut and or otherwise fashion a replacement spindle. You did say you were only missing one, correct?