Heritage birds were the production fowls of their day as far as the egg breeds, meat breeds, and dual purpose breeds; with each breed developed to fit the needs of the time and place. Function dictated form, and though a few characteristics [such as color] might have been aimed for to please the breeder's eye, these birds were the best of their day for production and the preferred bird to use when the breeds became standardized. Their appearance only gave evidence that they were pure and therefore likely to have the preferred production qualities. They were the best bird to own for the practical purpose of feeding the family and providing some cash income by selling eggs and/or meat locally. The heritage breeds became obsolete for production only because some breeders ignored form completely and bred or cross-bred for maximum production only. Breeding only to come as close to possible to the written description [standard of perfection for showing purposes] of what the breed is supposed to look like has, in my opinion, most probably had a bit of negative effect on the heritage breeds as far as their production qualities. Hatcheries sold chicks that were much closer in appearance to the heritage breed they were sold as 50 years ago; and I can remember a time when a show breeder's line might be scoffed at as a "show line" by an old timer sticking with the heritage breed that his family had been raising for many years. I realize such statements are often taken as insults by the people breeding chickens for the purpose of winning shows, but that is not my intent. These heritage breeds are still in existence, for the most part, only because of hobby/show breeders, and can still be utilized by those wanting them for the production qualities they were famous for. However, if you're wanting to profit by the sale of eating eggs or meat you are not going to compete with those using modern crosses or production lines. What you will have is a line of birds that can be kept year after year to feed your family without having to order chicks to replace them, possibly recoup some money by selling fresh eggs for eating, hatching eggs, or breeding stock, and the satisfaction of preserving the breed. Plus, if you want, you can show them.