J.J.,
It was not uncommon for people who lived in that part of New Brunswick, particularly Charlotte County, to move between there and Maine for work.
Anyone with ancestors who lived in Charlotte County should always check Washington County, Maine for them, too.
One of my g-g-grandmother's sisters was enumerated as a domestic in Calais, Maine in 1880 and at home in Charlotte County, New Brunswick in 1881. That was one of the few mistakes I've found on the LDS site: in their transcript, she was listed by the surname of the family she was working for but I found her in the original listed by her own surname.
My grandfather was born and raised in Charlotte County but his first marriage took place in Calais, Maine. It's just a short walk or drive across the bridge. (Well, it can take longer now at Customs.) My grandfather later moved to Saint John for work and spent the rest of his life there.
The George Moore who ended up in Quebec might have been the nephew of the one listed in the 1871 Lovell's in Saint John. The fact that there are two listed is interesting. If the George Moore in Saint Andrews was the son of one of the George Moores in Saint John, maybe the other George Moore in Saint John (if it was a different man) was his nephew.
It's too bad so many records were lost in the great fire in Saint John.
Sorry, I think I'm rambling...

Regards,
Josephine