They look fantastic, and those are very good qualities to be combining in a breed. How many hens and roosters did you start with to get those 27? Line breeding is the only manner I know of to get a closed flock to last, but that wouldn't do much for stabilizing genetics. After 6 years, I'd expect some inbreeding problems to show.
She still doesn't approve of my superhero lifestyle. Or this shameless plug:
the permaculture bootcamp in winter (plus half-assed holidays)