In reply to all:
A-ha, so yes, now we are getting somewhere:
1) Full English
2) Tie off belay (slippery wotsit and two half thingamees)
3) French prussick in front of belay, Klemheist strangling the ropes to anchors behind, link the two with a sling and 'ready' them to bite.
4) Release the tied off belay and pay out enough slack to allow prussicks to take the weight.
5) Attach the dead rope to the klemheist with an Italian Hitch and then release the sticht plate.
6) Tie off the italian hitch, make myself safe (cowstail into anchor rope/another prusick etc)
7) Escape system
8) Tie a double figure eight back into the rope I've just untied myself from and clip this into the 'biner which is still attached to the anchors but which is presently hanging flacid beneath the klemheist (effectively completing the belay system as it was, but without me tied into it). This double figure eight becoming the 'power-point'.
9) Clip a 'biner into the power-point and attach the dead rope from the tied off Italian Hitch.
10) Release the Klemheist Italian Hitch and take in the slack onto the new power point Italian Hitch and then tie this off.
11) Be strong and release the friction from the French Prussick taking the weight of the stricken climber onto Power-Point.
12) Dutch Courage
13) Do what I need to do using the remaining dead rope from the Power Point (remembering to attach it via it's own knot to the powerpoint 'biner if I'm abseiling and not simply ab off the tied off hitches on the Italian hitch).
14) Save the day, do another route.