(Source 1: Vs. Duck Hunt High Score Staff Initials)
Kenji Nakajima is spelled out in the high scores. Programmer from IS who was sub-contracted on several Nintendo R&D1 games.
(Source 2: Nintendo Dream: R&D1 Anniversary Interview Vol. I & II)
Japanese interview with Hiroji Kiyotake, Yoshio Sakamoto, Toru Osawa, and Kenji Yamamoto. Kiyotake is revealed as designer on Duck Hunt.
(Source 3: Hirokazu Tanaka Official Works)
Reveals Duck Hunt as one of his Nintendo soundtracks.
(Reference 1: Yokoi / Okada)
Yokoi was general manager of R&D1 from 1976-1995. Okada was deputy manager from 1976-1995). Respectively producer and co-producer / chief director of all R&D1 games.
(Reference 4: Yamamoto/Kano)
Not only were Masao Yamamoto and Makoto Kano second group in command under Yokoi and Okada, but they were also the creative planners for many games since the game & watch for R&D1 (Read Iwata Asks: Game & Watch). Yamamoto was linked to the NES Zapper in Japanese patents, and Kano was the original designer of the Beam Gun Custom series. The two men were linked to the NES Zapper, and then later again to the Super Scope.