Well, Barnabas certainly noticed Maggie and Josette's resemblance.... and dressed relatives up in their 1795 counterparts for the party. He was being very calculating when meeting the family, and would have been careful to keep quiet about anything which led to things he couldn't explain. "You look just like... well, someone I knew in 1795--- I mean, 1995-- what year is this again??!!!!" BC isn't about to screw up like that.
I usually think though that the eery resemblances were supposed to be some magical phenomenon peculiar to Vicki. Everyone may have looked identical only to her.