|The problem is with volume licence keys:|
I don't understand why the original installation was recognised for repair, but the restored image was not.
Unbelievably, it's now working, and I think that it was/is an MBR/MFT issue, because the successful boot into XP occurred when I set the Vista partition to be active!! I was always baffled by the fact that all the posts I found referring to hangs at crcdisk.sys were from Vista unfortunates, and here was my XP doing the same. Maybe it wasn't! Maybe it was Vista!!
So now I'm in, I'm reimaging, and plan to wipe the entire disk and restore just the xp image, tho I expect I'll have to reaquaint myself with MBR's and boot sectors, which I don't relish the thought of, but better than a reinstall with all the xp software I have loaded.
Thanks for your help, anyway.