I actually had some carp some old Cajun coon***** supposedly cooked in a pressure cooker and made almost a type of salmon patty out of them. From what I remember it was actually pretty good. Either that or all of the crawdads and beer I had could have made it just seem like it was good. They were from so far back in the swamp I couldn't hardly understand a word they were saying. But after a few hours I had Yak tongue so bad they probably couldn't understand me either. It was something else sitting around the campfire after dark and everyone there seemed like they could play some instrument. Kids from about the age of 3 to grandpa's in their 90's. They played all night long, Cajun and bluegrass music. The next day trying to fish was a day I will never ever forget. Bring on the carp!
My grandfather never threw away a carp when we would fish. My grandmother did something similar to what your talking about and we ate them like Salmon Croquettes. As a kid I never knew the difference.
We have also thrown them on the smoker and they were pretty tasty. Like mentioned get rid of the red veins.