There is a story, probably true, about the 1930s-40s comic actor W. C. Fields. He was originally from Philadelphia, and the area around Philly is where most of the scrapple lovers live. The story is that he loved scrapple enough that he had it shipped weekly from Philadelphia to his Hollywood home. I don't know how they kept it from spoiling during shipment back then. I had scrapple once, unknowingly, many years ago (fried), never had the desire again. In Texas, Menudo (sort of a soupy stew) is a big deal, mainly among Hispanics, not so much among Gringos. It's considered sort of a cure-all for everything that ails you (especially hangovers), sort of like chicken soup is in Jewish homes. I have eaten it only twice, both times because the circumstances under which it was offered would not allow me turn it down. There was a period back in the "Mad Cow Disease" scare when tripe (beef stomach) was not available to make it. Apparently "Mad Cow Disease" could be spread to humans by eating tripe from infected cattle. That is no longer the case. Some local supermarkets sell ready-made Menudo in the large restaurant-size cans. I have not seen scrapple (at least under that name) for sale in a Texas store, but I'd bet it could be found if I looked for it hard enough. But there is something probably similar to scrapple called Chorizo, a Mexican sausage which is popular among Hispanics in Texas.
Regarding sweetbreads, there is another Hispanic culinary creation popular in some parts of Texas, and probably in other areas where there is a large Hispanic presence, and that is Parillada. It is simply a platter containing a variety of grilled meats, which often includes sweetbreads. On the occasions I have eaten at a Parillada, I have avoided the sweetbreads. And then there is Lengua and Ojos, often used as meat fillings for tacos, enchiladas, burritos, etc.