Well success ! went with drill the heads off . used a 1/8 drill in the center went in about 1/8 in and then put a vicegrip on the screwdriver. little bit of muscle and the screw came right out . both times. lucky day for me. Thanks for the support.
So you're saying they unthreaded? Likely the heat from drilling that hole in the center was enough to loosen the hold on the threads from the rust.
Good Job!