Sorted !
A bit convoluted, but I managed by changing the e-mail address associated with the account. This generated a change notification to the original account (which shows I entered this correctly initially) . Changing back to the original e-mail address, I then received the confirmation request & the account is set up.
I have found many of the groups I used to follow, just can't find one operated by (IIRC) a gentleman called JW Early which had a number of articles scanned and very well "cleaned up" from '40s and '50s copies of Model Engineer. I can't remember the group name, but it is possible that Mr Early is no longer with us to transfer the group.
Thanks for the suggestions.
Nigel B.