Hi Cynthia,
I actually purchased 2 x 'F3C' male kittens. I reserved them at one week old and paid a deposit. I saw them with their mother at one week and was shown the father. I also saw the breeders pedigree for them. I visited again a couple of times and brought them home at 12 weeks having paid full UK F3 prices.
At 7 months and 4 days my silver/black spot boy was caught in the act with my daughter's little black DSH during her first season. We separated them and assumed obviously there would be no kittens but were still a bit shocked that he had even mated at 7 months! When she went to the vets to be neutered we were told she was pregnant. DNA testing done through our vet has proved the kittens were Bamba's. So I started asking questions. I called the breeder who agreed it was impossible for an F3C to be fertile. The dam of my boys was advertised by her breeder in Europe as an F2B and purchased by my breeder. Photos on the internet when she was advertised confirm that she is the same cat I saw and photographed with my kittens at one week old.
That's as far as I can go with my enquiries