I appreciate "classic". Also, as mentioned, interested ethically like Fergus Henderson, for example, in whole animal use, and the expansive, delicious
cuisine de misere frugal granny cooking that offal n bits represent. Being a snob about meat, or pretending the fancy cuts are Zen vegetarian and the haggis is disgusting suggests perhaps a little soul-searching might be in order. The lamb chop connected to the haggis. Would not exist without the haggis. And vice versa.
Bicyclette is bracing and bittersweet and simplicity defined.
www.nytimes.com
Larousse sez:
"pork and mutton, or with goose or duck"
Says there are three classic kinds:
Castelnaudary -- fresh pork, ham, knuckle of pork, fresh bacon skin
Carcasonne -- ditto, with the addition of shortened leg of mutton and partridge
Toulouse -- adds breast of pork, Toulouse sausage, mutton, and confit of duck or goose
It features two Castelnaudary recipes, both with breadcrumbs.
I don't think "knuckle" of pork can be construed as pig's or calf's foot. But Fanny's right, there's a good texture and taste you get from using them.