The definition of "potted meat" has to be stretched to include Underwood. The origins of potted meat was stuffing whatever was left over after slaughter into clay pots and adding a preservative. Different breeds and their various parts all went into the pot, or not, depending on what you had - kimchee for critters. As the pot filled you just kept smooshing it in. Modern canned meats from one breed, such as Spam or Underwood, might not qualify as potted meat, but there are definitely brands that do.
Anything like scrapple?
My understanding is that scrapple is more of a result of a recipe, and the meat portion of the recipe might be...questionable. A guy can boil a pig head and recover the protein and follow a recipe for scrapple, or can the stuff for potted meat.
