Prepare the pressure canner, jars, lids, and bands, and keep the jars hot.
Pick the cooked turkey off the bones and shred it into bite-size pieces, leaving out the skin, bones, and gristle.
Peel and dice the potatoes, and chop the onions.
Put the turkey, potatoes, and onions in a large pot with the salt, poultry seasoning, pepper, and wine, and add enough broth to cover.
Bring to a boil, then reduce the heat and simmer for 5 minutes. Keep extra broth hot for topping off the jars.
Use a slotted spoon to fill the hot jars with turkey and vegetables to about 1 inch from the rim, full but not jam-packed.
Ladle hot broth over the solids, leaving 1 inch headspace.
Remove air bubbles, check the headspace again, and top up with hot broth to keep 1 inch.
Wipe the rims, set the lids on, and apply the bands fingertip tight.
Load the jars into the pressure canner, lock the lid, and vent a steady stream of steam for 10 minutes before adding the weight or closing the petcock.
Process at 10 lbs pressure in a weighted gauge canner or 11 lbs in a dial gauge canner, quarts for 90 minutes or pints for 75 minutes, adjusting for altitude (see notes).
Turn off the heat and let the canner return to zero pressure on its own. Remove the weight, wait 5 minutes, then remove the lid.
Leave the jars in the canner 10 more minutes, then lift them onto a towel-lined counter to cool undisturbed for 12 to 24 hours.
Check the seals, remove the bands, label the jars, and store them in a cool, dark place.