Mister Dapple is otherwise unknown, but compare "Southern Uncle, Mr. Dapple" in 4:06, and 8:08, who also talks with Yancheng Ziyou; Southern Uncle, Mr. Flower in 6.04; and "Mr. Dapple of the East Wall," with Yancheng Ziyou, again, in 8:09. There is also a "Fitfriend of South Market" in 8:14 and 14:02; and a Mister East Wall in13:04
According to tradition, Yancheng Ziyou was 45 years younger than Confucius, which places him around 500-425. In 8:08, however, Mr. Dapple is visited by Tian He, a historical figure who is known to have died in 384. Since the dates are incongruous, either the various Mr. Dapples are not the same guy or the stories are not meant to be historical.