Handbrake cable snapped

I recently got a 1986 ex military soft top 90 - so I'm hoping winter will stop soon! The handbrake had been getting worse and finally, the cable snapped. I had a quick look and realised it was a transmission brake like a Series 3 I had a long, long time ago.
The cable was actually 3 cables inside the single inner - is that normal?

Would be grateful for some advice on fitting a new cable.

First thing is does anyone know the cable part number?
Second thing is how is it fitted?
Lastly, should I take the brake apart and check it's OK? If so, how would I do that and what will I find inside?

Any information will be gratefully received
Cheers, Dave

Standard defender 90 parts, nothing special.

Yes strip and inspect if it isn’t working properly

Always handy for finding part numbers:- https://www.landroverworkshop.com/diagrams