Can anyone shed light on parking brake cables.. ?

I'm not aware of all the different changes over the years, but generally, you have two cables out of the rear wheels, with a little "C" shaped slotted connector, and that forms the forward loop, with the equalizer / slider delieee thingy, and that then hook into the forward cable up to the lever mechanism

The following are shots out of the 67, 70, and 72 manuals, so you can see there've been changes