Try your local grocery store . Ask the butcher . In winter they often have it packaged and out in one of the meat coolers . People buy it to feed the wild birds .
This can be cured . There are different cures . The one I use works for me . I use a dog nail clipper to trim the beak back to where it bleeds . Have some blood stop powder on hand before you start . Most farm stores carry this .I think I got mine at Tractor Supply . I also put a golf ball in...
Don't know on the avocado but grapes seem ok . I know of several people who let the chickens help themselves to grapes with no ill effects . I recently visited a guy who has a large area enclosed with 6 foot chain link fence . He planted 50 vines around the fence and plans to keep planting more...
Mine love tomatoes , squash and melon rinds . I raise extra tomatoes , squash and pumpkins for them . Pumpkins will keep in the garden until they freeze . Makes nice treats when everything else is gone .