I've repeated this about a gazillion times, here goes again:
Tough old birds go in the crock pot, pressure cooker, or get pressure canned. They all get tender eventually in the crock pot, a lot faster in the pressure cooker or canner. If you pressure can, boneless turns out the best, the smaller bones get crumbly and hard to remove. However, pressure canned bones can be fed to your pets, they get soft and don't splinter.
I usually use the crock pot, because it's so easy. Season it, put it in the pot, add a little water (about 2 cups), put the lid on, plug it in and set it on either high or low, I've had great results with both. I use low if I start it at bedtime and let it cook overnight. You truly do set it and forget it, go on about your business. On high it usually takes anywhere from 5-7 hours, depending on age, breed, and gender. I think hens get tender a little sooner, but that could be wrong, I haven't cooked a lot of hens. When you check it after about 6 hours, if it's not falling off the bones yet, just wait. It'll get there.
I take the meat off the bones, chop it up a little and use it in all kinds of dishes. I favor Mexican. Chicken tacos, enchiladas, tamales, burritos, but also stuff like BBQ sandwiches, chicken salad, stir fry, or even just hunks of cooked chicken as the meat for a meal. I like a cup of the rich, dark, broth to dip it in. Once, I made "chicken-dip sandwiches", chicken meat on hard rolls, with the broth to dip it in, just like the beef French dip sandwiches. I have friends I get together with regularly, and we take turns bringing food. I often bring a whole crock-pot bird, and broth, and they love it. You can put the strained broth back in the crock pot, (you may want to slim the fat first, if there's a lot) use the broth instead of plain water to cook some brown rice. Add some of the chopped up chicken meat, and a few veggies if you like, and it's really tasty. And good for you, too.
Any left over broth gets frozen for later use. It'll be darker than you're used to seeing, and the flavor is amazing. It's great for sauces, gravy, and anything you'd use canned or boxed broth for. I never buy that crap anymore, the broth from my own birds is so much better. No chemical crap in it either, and I control the salt content.
Speaking of salt, the meat will be more moist and succulent if you soak it in brine overnight before you cook it. The salt gets into the tissues, and that holds the moisture in. Otherwise, the meat can turn out dry, even with slow, moist cooking.