Heritage breed chicken cooking techniques needed

As I've mentioned to a few here, Gail and I have jumped into raising our own flock of heritage breed chickens. Most are for the eggs, but some are destined for the table, and the one bird we've cooked so far (a Dark Brahma pullet @ about 20 weeks) was, shall we say, tough as jerky, albeit very flavorfull. That bird was skinned iso plucked, and hit the oven within a couple of hours of being dressed, basted with broth and drizzled with EVOO. It probably should have had a couple days in the fridge first.
We are about to try again, and need some advice as to cooking a non-factory farmed bird so as to have a reasonably tender result.

I'll jump in with the obvious: wet methods (braise, stew).

For the heritage breed turkey that I do at T'Giving time, I roast the bird upside-down for 2/3 of the cooking time so that the moisture runs down into the breast.

I bought a freshly dressed, local free-range bird last year and was told to refrigerate for at least 1 day. As bad as it sounds, they said no rigor mortis = no good.

Over the course of the rest of 2012, we'll be cooking birds of at least a dozen breeds, in an edible experiment to determine which will become our future mainstay meat breed. Cornish Cross birds will NOT be in the mix, but parent breeds of those misbegotten hybrids will be - Plymouth Rock and Dark Cornish chicks (along with New Hampshire Reds, Turkens and Easter Eggers) are in the brooder on the back porch as I type this.

I can't talk knowledgably about breeds but I know someone who can: The guys I buy from do a blog:
http://www.ruralintelligence.com/index.php/blog_section/blog_articles_AgriCulture/

If you go to the archive there is an article about breeds from Feb 2, 2010. They are also both really nice, helpful guys. You can shoot them an email and I'm sure they'll answer.

In the past we used to raise 25 or more chickens of various breeds now called heritage or exotics (various Cochins, Cornish, Jersey Giant, Buff Orphington, Astrolorps, various Rocks, Hamps, R.I. Reds, all the middle or heavy weight breeds). My son even took an open class blue ribbon with his white Cochin Rooster at the Minnesota State Fair.

Chicken muscle is like any other creature muscle. The more excercise the chicken gets the more developed and tougher the muscle will be. With our older birds we first fed them a diet that would fatten them before we butchered them. This made for a moist rich tasting end product. After butchering we dipped them into hot water to loosen the feathers and plucked the feathers. Removal of the skin combined with not having a fat older bird leads to dry tough meat. With the older birds we always cooked them low and slow whether pan fried or baked. Unless it was an old rooster the legs were always sufficiently tender. Care had to be taken when slicing the large cooked breasts though. You needed to use a sharp knife and cut across the grain otherwise the meat would be stringy.

Now I seldom eat chicken because I was spoiled by the flavor and abundant muscles of the home grown. The mushy meat sold in the stores IMHO is quite distasteful.

Coq au vin if it's that tough?