Thank you very much to all of you for the details and the pictures. I had looked on pictures of accelerator cables on Google, and I was wondering what kind of end was this plastic piece

. Now Kev and mgglep, I understand it fits on a ball-nipple

.
But without the donor car, I think I will have hard time finding this ball-nipple piece that looks to be found on the original accelerator pedal. I can plan for a ball end cable and a clevis as Skov, very clever, and it looks quite easy to do out of a folded and drilled 1mm steel plate, or drill the plastic socket from the Sierra cable to fit it with a bolt through it. Anyway, I see clearer now.
Thanks you very much again.
Sylvain