Holy Maloney....I've cracked it
A combination of your ideas.
"drill out the holes to feed outer and inner through frame."
Yes, good idea but I didn't want to ruin the integrity of the design.
"thread strong wire through first, attach cable and gently pull through"
Yes...but the internal ferrules narrow to inner cable diameter"
The solution....well the internal ferrules were well stuck in the frame. I used a L section of a small allen key to hook the inside and gently pull the ferrules out. Slowly slowly catchy monkey.
With them out I threaded a section of outer cable (shorter than inner cable length) through the frame. After about 20 wiggles, turning the frame around, one cup of coffee, the end came out the exit. EUREKA!
Now a simple job of threading through the inner, remembering to attach everything, inner ferrule, outer ferrule, outer cable etc first.
Once through pull the outer 'guide' cable out. Job Done.
How happy am I
Cheers for the help