All of those dishes look delicious (once I learned the first wasn't a heart with eyeballs). If I lived with you I'd probably weigh over 300#!
As for cow heart, I've never tasted one; but I've had pork heart before. I was just a kid; remember eating quite a bit of it before I was full. It evidently was very tasty. In the mid 60s, I worked in a meat market. We had several customers that wanted some items that were unusual to most people. One family bought several beef tongues per month. We also sold chitlins, beef tripe, 'head cheese' (souse?), and several other things that are very seldom seen today.