What is the origin of "TOON"

From what I've read, it's how "town" is pronounced.

 

That is correct. People from the places around Newcastle would refer to it as "the Toon", being the largest city nearby.

For example, as in "A'm gannin to the Toon" - "I am going to the town [Newcastle]".

 

' Hawy Enrique', lets gan doon the toon '. Its just regional dialect.