In the past I have had good luck with the flat topped drill bit that came with my Dremel tool with working with pewter so that is the one I chose for this task. As in the past, it performed marvelously. The hardest part to deal with was the heat buildup. I overcame this by dipping the model in water when it became too hot.
I hollowed out a suitable area for the new head and then polished it up as best I could.
Next I will unveil the head and we will see how it fits.