Hi! (as usual, my excuses for my spanglish).

I have a similar experience last March, I've a Amazon 121 witha a B18A engine (similar coil) and live on Lima, Peru (Southamerica).

We have limited volvo supplies here, and due it, after my coil goes south, I cut the armored cable at the coil, and after it make another cut at 5 cms leaving 5 cms of (+) cable hanging.

I patch it with a 12 gauge electrical cable (extension) and a VERY GOOD aislant (some plastic tube shrinking with heat would be fine, i adquire mine on radio shack).

In my case the new cable extension goes to the engine bay trought the same hole of the accelerator (a hole over the big one of the coil), and I cover the big coil hole with a metalic "L", and use it as a support for a new blue coil.

I use a lime for kill the cutting borders of the armored cable. Also, I attach the metalic end of the cable to the firewall with a metalic hook/bracket (like the ones use for attach the fuel line to the pump plus a screw).

You can see a photo of it (from the engine bay) under the "update" section on:

http://www.volvoadventures.com/121spec.html

Have a volvo day!

Joaquin
Rojo 121 Amazon
Lima-Peru