re: Best way to cook 2/1.3lb fryers in cast iron dutch oven?

First thing you need to clear up is are they fryers or hens... Fryers don't need to cook nearly as long as a hen but since the weight in them is 1.3lb, you probably have 2 small fryers.
Having got that out of the way, I'd say put a little oil in te bottom of the pot, season the fryers well, stuff the cavity with a couple of links of smoked sausage (or you can just put the smoked sausage links around the chicken in te pot) & some onion, cover them up & bake in the oven, after about an hour, uncover, add a little chicken stock, chopped onions, & water, and cook uncovered for about a half hour until skin gets golden brown. Serve gravy over medium grain rice & enjoy.