So I have a few frozen packages of pork tongue, heart, and hocks from a half a butchered pig we got. My idea was to use these muscley bits to make sausage. I have some fat that I trimmed from a picnic ham I used to make a squash-pork stew. I after thawing, cleaning, and analyzing the tongue and other bits, I can probably guesstimate the meat-to-fat ratio to get in a sausage making range.
The question is, can I use the tongue, heart, and and hocks for sausage? I'm planning on making half batches of each of Ruhlman and Polcyn's Charcuterie two Italian sausage recipes, and those call for shoulder. Can I substitute these other hunks of muscle?