Everything is straight, cleaned and oiled. The parts you mentioned all move fluidly and flawlessly. I am using the correct needles and they have been installed correctly. I'm guessing, for a 116 year old machine that parts are worn and I was expecting that. But I was also expecting her to stitch but it's clear that a previous owner has, most definitely been messing with the machine and trying to remove parts and failed. There are broken screws, missing screws and marks here and there, consistent with my theory.
I don't know how long the machine was standing idle before I got her and the insides were practically bone dry. She isn't producing stitches although she does pick up the bottom thread initially. As I've said before, the problem is with the needle piercing the leather too early, thus stopping the leather from feeding. When I attempt to run the machine with no thread, only 1 hole is produced in the leather because the leather isn't feeding.
I shall try another few suggestions that I've been offered here. Thank you very much for your input.
Arwel.