Dear Mr. Bennett,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located World War II Combat Operations Reports, 1941 - 1946 (also referred to as Mission Reports) in the Records of the Army Air Forces (Record Group 18), which includes the files 347th Fighter Group: Diary Log - Guadalcanal August 20, 1942 - December 31, 1943 and 347th Fighter Group: Narrative Mission Reports September 20, 1942 - September 27, 1943. We also located World War II Action and Operational Reports, 12/7/1941 - 1946 in the Records of the Office of the Chief of Naval Operations (Record Group 38) which includes action reports from Commander, Air Solomons (AIRSOLS). The record series titled Serial Files of the Naval Security Group Central Depository at Crane, Indiana, ca. 1914 - 5/6/1981 in Record Group 38 includes four files relating to the Yamamoto shootdown.
We also searched online and located “Killing a Peacock: A Case Study of the Targeted Killing of Admiral Isoroku Yamamoto” by Maj Adonis C. Arvanitakis, School of Advanced Military Studies United States Army Command and General Staff College, January 2015. The paper includes footnotes and a bibliography listing a number of primary and secondary sources. Many of the sources listed are in the custody of the Air Force Historical Research Agency (AFHRA.
Many of the historical and operational records of the US Army Air Force have been microfilmed by the (AFHRA). The National Archives at College Park - Textual Reference (RDT2) has a copy of the microfilm. For access to the microfilm, please use the index to the Air Force History microfilm available at http://www.airforcehistoryindex.org/.
To conduct your search for 339th Fighter Squadron records, please enter SQUADRON/0339/FIGHTER in the search window of the index and narrow your search by including 12/7/1941 in the Start Date and 12/31/1945 in the End Date before clicking the Search button. To search for the 347th Fighter Group, search for GROUP/0347/FIGHTER. You can also search by other key words, such as Yamamoto. Read the brief Abstract to determine which records you are interested in and click on the specific PDF icon. In the PDF listing, the IRISREF is the microfilm reel number and note the FRAME and FRAMELST numbers for the location on the reel. If the reel number begins with A, B or C, please contact RDT2 via email at firstname.lastname@example.org for access to them.
If the reel number begins with D - Z, the microfilm is still security classified and RDT2 will not be able to make the reel available to you. The original paper copy from which the film was created is still in the custody of the AFHRA and has been declassified. For access to these records, please send a reference request via their Contact Form.
We hope this information is helpful. Best of luck with your research!