Stower, yes you're right. A quick look on the Net shows that Lee wrote Watchman in the mid-50s, while Mockingbird was published in 1960. That was not apparent in the Radio 4 discussion I heard. I agree as well that Atticus Finch (and no doubt the character of Scout as well) should not be assumed to be identical in both works.

The introduction to the programme said that Watchman was found stored in a bank vault, and Lee, who is now 89 and in care in a residential home, gave permission for its publication. Certainly the publishers are going to make money out of this, but - who knows? - maybe Lee feels her financial reserves need topping up as well.

The two guests on the programme certainly did not think that the book has no literary merit, but they agreed that it should be thought of as a draft rather than as a finished piece. Bonnie Greer made the point that the Atticus Finch in Mockingbird could not be anything other than racist, given the time and place in which the story is set, and his social status.