http://michaelanthonysteele.com/index.php?s=Hardy+Boys&x=0&y=0
Michael Anthony Steele was the ghostwriter for "Deception on the Set" and "Showdown at Widow Creek".
Nice! Thanks for tracking down the information.
As the title says, there's been a major update. I suspected that since Michael Anthony Steele revealed himself as a ghostwriter, he probably wouldn't be writing anymore Hardy Boys. Looks like S and S doesn't care really about ghostwriters revealing their identities anymore.
According to his website, he's ghostwritten "Attack of the Bayport Beast" and "Stolen Identity".