I always assumed that area of Canton was all built at the same time? Maybe I'm wrong, but the notion that it was simply a case of the wrong signs being put up sounds plausible to me.
As for Abergorki - although the spelling is slightly different, it seems Abergorky is still a district of Treorchy with this building a testimony to that
https://cinematreasures.org/theaters/28029
When we've got a train service up here, Abergorki industrial estate (that term makes it sound grander than it is!) can be seen from the train between Ynyswen and Treherbert stations - Treherbert being the last stop on the line.
There was also an Abergorki colliery;
https://www.welshcoalmines.co.uk/Gla...kiTreorchi.htm
Wonder if the Insole pub in Canton was named after the family mentioned in the article about the colliery?