I've got all the grid filled in (so if anyone wants a hint to a clue just ask!), I know the thematic source. But, I haven't got enough correct/extra letters to provide a written response to the mistakes - so I can't highlight the grid. I've just Googled the 'source' but am still none the wiser!
Any help very gratefully received!
The response is very similar to a kick yourself moment - verbalised as ...
Identify the character... famous for the verbalising and you'll work out what needs highlighting.
...Ripper, sorry - the R is correct but there's a letter after the E. And your N may be correct too - I didn't realise that you might still have letters to get there. The whole thing is ??NOYE? ?R?N?.