The night attacks on Munda started in January, 1943. A decision was made to use Black Cat PBYs (out of Guadalcanal) as spotters.
https://warfarehistorynetwork.com/ar...ault-on-munda/
In planning the attacks:
"After polling his cruiser commanders, the admiral (Ainsworth) concluded the Curtiss SOC seaplanes carried aboard the warships were not well suited for night bombardments and thus would not play a major role in the mission. Therefore, a number of Black Cats––Catalina PBY seaplanes specially equipped with radar for night operations––were placed at his disposal."
Another paragraph in the above link mentions that Aviation Officer Crowley (from Ainsworth's staff) along with two well trained aviation spotters were sent to Guadalcanal to ride along on the Black Cat missions. I think Duncan was one of the "well trained spotters". That would match up with the newspaper articles in the post above, which mentions Crowley, Duncan and Barnett. They were all "pilots" but may not have been flying the Black Cats on the missions.
Here is a clip on Marvin Everett Barnett, from Florida. Note he was Senior Pilot on a cruiser (USS Honolulu?).
https://www.newspapers.com/article/t...mes/127500060/
Same story with Crowley "slant".
https://www.newspapers.com/article/t...ews/127530738/
A more detailed description:
https://www.history.navy.mil/researc...-stanmore.html
Five attacks on Munda area are discussed in the last link all used Black Cat spotters. You can download the 79 page text, or just scroll down the page to read it online. Attacks went from January to May.