Adult Son of Canadian Father wanting Citizenship

I am an adult son, born in 1964, of a Canadian father. He served in the Canadian Army during World War II and still receives a Canadian Army pension. He moved to the USA after the war and has stayed since as a dual citizen.

There seems to be a gray area in Canadian citizenship if you were born after 1947 and before 1977 abroad to Canadian parents.

I want to claim my Canadian citizenship if possible and live in Canada the rest of my life.

Is it a lost cause to try and become a citizen as a child born outside Canada to a Canadian father this late in life?.....I really didn't know i could do this until yesterday. Is it too late???????

I can apply for spousal sponsorship since i married a Canadian, but it will take 6-12 months and $ 1500.00. If i can claim citizenship through my Canadian father it will take only 1-3 months and only $75.00 to apply for.

HELP!

JC