David McDaniel wrote several of the Ace U.N.C.L.E. paperbacks and was a fan not a hack. after the series' cancellations he wrote The Final Affair, his own version of the resolution of the series concepts.
It was never published, and for years/decades was a rumor and hard to find. For more info on McDaniels, here is one source: http://www.manfromuncle.org/mcdanielbystine1.htm
Now, with permission from a Cousin, here is a PDF of the text. It's been available in other places online, but sharing is good!
Here is the link: http://www.mediafire.com/?0okhzm69zywi6bs
See you next time!