Good to see your interest in the fancy. Since you purchased them locally, I wonder if they could be descendants of the ones I had. I am anxious to see them at the show. Yes, you can breed father to daughter or mother to son. This is what breeders do to produce uniformity in their birds. It does eventually lead to decreased vigor, but you can take those two birds and make a flock. I understand that it is not best to breed full brothers and sisters together. I have found that serious breeders keep more than one "family" group of the same breed and variety. That way they can bring in new blood without bringing in characteristics they don't want.
Also, things are different now than years ago, adult birds can now be shipped through the postal service. And with the internet, I'm sure we can find you enough good birds to give you a good start.