Was #83 or #85 the last Stratemeyer Syndicate title?

[OldHardyBoysFan]

Was #83 (The Swamp Monster) or #85 (The Skyfire Puzzle) the last Stratmeyer Syndicate title?

I'm asking because the http://hardyboys.us/hbdigests.htm web page says:

"#83 The Swamp Monster was the last book penned by Stratemeyer ghost writers. The final edits were done by Simon & Schuster.  After producing volumes 84 (Revenge of the Desert Phantom) and 85 (The Skyfire Puzzle) in-house, Simon and Schuster farmed out creation of new stories to Mega-Books."

But the same web page also says Neal Barrett was the ghostwriter for both 83 & 85.  So was he a Stratemeyer Syndicate or Simon & Schuster ghost?

I know the cannon is 1-58, but I can see the end of Syndicate's titles as the cutoff for last of the "real" Hardy Boys titles.

[tomswift2002]

#80 "The Roaring River Mystery" was the last fully completed Stratemeyer title.  #'s 81-83 had all been approve by the Stratemeyer Syndicate before the sale to Simon & Schuster and were in various stages of being written/ edited.  #'s 84 & 85 were Simon & Schuster's first books that they commissioned and had full control over from beginning to the final published title.  As for Neil Barrett, as far as I can recall, nothing's surfaced in relation to #79 "Sky Sabotage" and him being the author, however #85 "The Skyfire Puzzle" is a sequel story to #79, so he might've been hired for #85 because he wrote #79, however there is no evidence as of yet.

[OldHardyBoysFan]

Thanks. This is the list of authors for #59-#85 given at that web page.  Sounds like it may include some guesses:

Neal Barrett: 83, 85
Vincent Buranelli: 61, 63, 64, 65, 71, 75, 77
Richard Deming: 66
Conrad Fuchs: 68
Karl Herr III: 70, 72, 78, 80
Jim Lawrence: 59, 60, 62, 67, 74
Laurence Swinburne: 73, 76
No Author Given: 69, 79,  81, 82, 84

[OldHardyBoysFan]

This is the listing per the James Keeline website:

Neal Barrett Jr.: 83, 
Vincent Buranelli: 61, 63, 64, 65, 71, 75, 77
Richard Deming: 66
Conrad Fuchs: 68
Karl Herr III: 70, 72, 78, 80
James D. Lawrence: 59, 60, 62, 67, 74
Laurence Swinburne: 69, 73, 76
No Author Given: 79, 81, 82, 84, 85