Using the old string as a guide, cut two new lengths of string for the fingers - one is doubled up, the other single, and both feed into the tension equalizer:
This was the tricky bit... Clamping the string into place with these grub-screws which had a nasty habit of spinning and pulling on the string... at that same time, keeping an eye on the lengths to ensure they are even.
I found a steel rod helped keep things in place until tightening. Ideally, you need two Allen Keys for locking these grub screws - you tighten one clockwise, the other is tightened anticlockwise, and should counteract things. I only had one, and certainly was a struggle!
With the equalizer in place, I could now make a start on the remaining string which is the grip action cable.
The gripper cable starts from the rear drum (locked by grub screw), feeding forward, before returning to the idler pulley next to the drum where it all started:
The end of the string will be hooked onto the shoulder spring, so I have simply clipped this to keep in place until then. Masking tape keeps the reduction gear from rotating, and also keeps excess string out of the way.
Arm ready for installation: