Finn juhl diplomat assembly  

From what I remember there are brass rods between the seat and the frame.
Are you able to post pictures?

are you talking about the...
are you talking about the metal 90deg strap that holds the back to the seat, only exposed screws under the seat?

Finn juhl diplomat chair
Yes it has a small black bracket attached to the back,and the holes in the bracket does not line up with holes on base of chair..
Also it seams like a short bracket ( about 3")to hold the back of chair.
I'm sorry I don't know how to post pictures
Thanks
Soflinka

The L shaped bracket should...
The L shaped bracket should be connected to the back by small metal screws which are hidden underneath the upholstery then the other end of the bracket is screwed to the underside of the seat with the same metal screws, sometimes if the chair/s have been taken apart and re-upholstered the holes don't quite line up especially if the bracket is placed over uneven fabric etc. They are quite tight to get to line up at times, and I have found on mine which have had the same issue that you just start the screws and not fully tighten before you connect the seat to the back then once you are able to line it up then tighten the screws. hope that helps.