Since you like floatplanes so much here's another clip from the NHK collection featuring Kawanishi E7K2 "Alf" & Nakajima E8N "Dave" in action. The video is dated November 20, 1940 and the title is "Umiwashi Tsubasha wo Tsurane Yuyaku Konan Kyushu" (The lined up wings of the sea-eagles surprise attack Jiangnan in high spirits).
The narrator explains:
"Our wild eagles freely attack continental China in all directions with gradually increasing success. The Navy units of Central China achieved amazing results. In early November a part of our seaplane unit force departed from their base flying over the cold autumn waters and attacked the remnants of enemy units in the mountains of Anhui Province.
Performing dive attacks they annihilate the enemy and even surprise attacked enemy positions around Jingdezhen. They also targeted and dive bombed newly built enemy barracks, destroying them completely. After confirming their success all aircraft returned to base without the slightest problem."
The tail marking of the "Daves" is clear close to the end of the clip and is "V-3" for the seaplane closer to the camera. The "V" marking is usually associated with the Tainan Kokutai which was equipped with Zeros, so the unit is elusive for now. If you have any suggestions leave a comment.
More stills showing the tail marking.