Well, DriveImage XML didn't want to play, but EASEUS Partition Manager did the business (thanks, Bushfiva) and the SATA drive is now partitioned and has a clone of the Win 7 boot drive on it. I've not sussed how to tell it to boot from that one, but that's for another day.
EASEUS is like the Partition Magic I used to use many moons ago. I'm not sure if I'm brave enough yet to use it to resize "live" partitions, but I think I'll give it a go once I've backed up the one that's getting a tad full.
The problem now is that I'm running out of alphabet for drives! I've even "recycled" X: which was the SCSI DVDROM drive that doesn't work because there are no Win7 SCSI drivers for the card. Some rationalisation may be called for.