Thanx for replying - I had done that but still nothing happened. I checked the mobi metadata and the authors were actually still in LN, FN format from my original naming convention.
I found an old post which mentioned the Kindle possibly caching the metadata info and to make sure to Restart it before resending files.
Tried this with one of my collections and it seemed to work - so I will now remove all books, restart the kindle & resend them - fingers crossed
