Canning is definitely the way to go with older birds...everything comes out tender when pressure canned!

It helps to have your meats in a jar too, when the power goes out in the winter months....last year it did that here for a week and a half and I hadn't canned up all the CX I had processed in the summer. Fifty odd meat birds had to be farmed out to strangers who still had power and I never did get even a fraction of those back. All that work, all that money...poof! Never again if I can help it.
I hate depending upon the power grid....

We homesteaded without it when I was growing up so still not used to all the downsides of living tied to the utility octopus.