IMO you have all the bolts out. I would not hit the fins with anything yet (too late). I use a teeny tiny chisel, 1/8 or 3/16", placed right into the head gasket. Probably in the rear first. Tap it with a solid hammer till you hear the tone change meaning the gasket has let go. Then work around.
Do not go deep with the chisel, just enough for a tone change, 1/4' or less. Last resort to do this, can't be helped.
Usually it just pulls apart.