OK Gents, I think there's some progress.
I noticed, just before the repair option appeared, that there was the briefest of appearances of the screen inviting fresh installation or repair.
I booted from the CD once more and just managed to stop proceedings at the correct spot. The machine is now about 40% of the way through copying files.
I can't emphasise how brief was the appearance of the options screen.
Thanks again, chaps.
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