Well, Well, Well! All is back to normal. I eventually found the Snap 2200 disk image file, and after following the instructions, the 2200 read one disk. Then the 2200 did an automatic formatting repair for the second disk, after which the Raid 1 could be recreated.
Moral of the story is "Do not use any Snap disk in another system", unless it is to, of course, rescue yourself from using a Snap Disk in another system!
Thanks to the guys who helped on this one.
Best wishes
Mel
Just an afterthought - Can we get the wiki back online? - There's still SnapServer life out there!