revisiting seatback release issue 1987 carrera

[dgc2]

finally reached the point of addressing the seatback release issue on my 87 carrera. prior blogs 'solved' this by pushing seatback backwards before moving release
tab upwards. took off the levers and trim on both sides and the plastic covers on the bottom corners of the seatback. cables are fine and lubricated. levers at the bottom
of the cable release ok when moved by hand. inboard lever stucks with backward pressure on the seatback (i.e. sitting in the seat). and yes, pressing seatback rearward releases the stuck tab. played with the bolts attaching seatback to bottom hoping for an adjustment, but no help. i would pull the seatback off for a closer look, but before this i would need some hints on what to look for.

so not wanting to beat this issue again, but does anyone have any successful hints?

thanks,
dgc2