['68OrangeSunshine]

I think '67s have a coolness factor all their own, so since you're halfway there already, I'd cover over the marker holes on the two fenders that are later than '67.
That depends on Canadian safety laws, however. If that's legal, I mean.
Does the cab have a small rear window? If so then 1967 all the way.
'68s have reflector-only markers, later years had lights, and even later, turn signals in front.