That line about Cheggers is so beautiful and perfect that one suspects Mr Chegwin became and alcoholic just so he could use it.
On the question of whether it this spread to the colonies, I will comment with regard to Australia. “Soccer” is the main term in Australia for that form of football. “Rugger” and “footer” are not terms Australians use: the terms would be associated with upper class English speakers. Fiver and tenner have some currency (no pun intended) particularly among older Australians. I have not heard any of these other -er examples used by Australians. The -o and -y endings are more common in Australian English.
The author links the Australian tendency to form nicknames using the -zza ending with the Oxford -er: it’s possible there’s a connection, I suppose.