Alan King here. Tried again this pm to get into one or other of these accounts - and MAGICALLY!!! - I was allowed into one of them. I don't understand what I did that was different, maybe YAHOO had temporarily locked me out - don't know. If they did they did not say they were going to, or that they had, or that they had released it.
Anyway, once I was in I changed the password and changed the verification email address. Got the 8 digit code and this allowed me get into the other one, where I did the same thing.
Problem solved.
But YAHOO are a law unto themselves it seems.