Coordinate system (x,y) where bottom left = (1,1).
The above have been fixed.
As of today, all the above along with other minor typos have been fixed. In Huang Longshi's biography, the current version now reads, "It is said that he is 13 dan in fighting." Go Seigen did not say directly that Huang was 13 dan. In his preface to Chen Zude's Ancient Chinese Go Games with Detailed Commentary Series, he wrote in one paragraph that Meijin Dosaku was regarded as 13 dan, and in the subsequent paragraph, that the daguoshous of the Qing dynasty were comparable to the level of Meijin. Therefore, I suspect that people may have made the following inference:
Huang ~ Daguoshou of Qing dynasty ~ Meijin ~ Dosaku ~ 13 dan
and misattributed the quote to Go Seigen.
I apologize for the errors and any inconvenience.