Regarding Sobers, yes he was knighted by Barbados. When I looked at the list in Wikipedia it showed him as
Sir Garfield St Aubrun Sobers, AO, OCC. When I clicked on the "AO", it took me to the Order of Australia page and the first thing you see is the Insignia of a Knight/Dame of the Order of Australia.
That confused me but then I found out he had the dual nationality. So he's a Knight, he's Australian and he's a member of an Australian order of chivalry. That's why I thought it had been awarded by Australia. If he was Knighted by Barbados why no other letters after his name?
It turns out Barbados didn't nominate him because they had stopped putting their folk forward for UK honours, it was done by the UK. As he's a Knight Bachelor, that's the lowest rank and as he's not a member of any Order, there are NO letters after his name.
There you have it, I was wrong but at least I've learnt a new thing about Knights.