to clarify my rambling above, a flat hammer on a flat panel doesn't work well at all at pushing/capturing excess into the dolly. you'll be there forever with no results.
Hence the crowned hammer on a flat panel, to push excess into the donut. Just as I mentioned the pin point accuracy of a heating tip, with a donut dolly I prefer sized at the diameter of the hammer face or slightly larger. Usually with the crowned hammer I use same size diameter dolly as the hammer, as the edges don't really hit. This smaller size allows more precision in bringing down the high spots when it isn't a good consistent bulge. Like the ones you show, the sanding shows highs and lows, so a smaller donut would allow better precision in picking out only the high spots.
