Got the numbers:
Fast idle
0.098% CO (limit is 0.200)
23ppm HC (limit is 200)
1.008 lambda (between 0.970 and 1.030)
Natural idle
0.019% CO (limit is 0.300)
Not bad for a car that gets hammered and has a £15 no-name lambda sensor
But sadly I think this is her last MOT. Strut tops are dying, steering rack is on the way out, gearbox is getting noisy, clutch is on its last legs, rear subframe bushes are totally shot (and non-replacable), rust along the top of the windscreen and the FK shocks are wearing out. Thats way more than the poor thing is worth.