I don't know how similar snapper meat is to a softshell turtle, but we used to catch big assed softshells on out trotlines growing up in Texas, and we would make stew out of them.
No special recipe, just boil the meat, take out the fat that floats up, and repeat until no fat floats up, then set the meat aside, make a roux, and put in anything you have on hand that would make good gumbo or stew fixins. I like to make mine with Rotel tomatoes, okra, yellow squash, onions, bell peppers, lotsa hot shit, and a couple of cut up boiled potatoes (preferably leftover potatoes from the last crawfish boil, if ya got'em). Some salt and bay leaves to taste also. Throw it all in a big pot with the roux and meat, stir and simmer it until all the veggies are tender. If it gets too thick, add some water or beer(preferably Lone Star if ya got it). Get mama to make some cornbread while all this is going on, and prepare for culinary bliss, my man.
P.S. Save some for me!!