Thanks for all the interesting advice! I'm sure it applies, not just to this case, but to plenty of other situations which gamers are facing.
As it turned out, this repair was rather easy...
Bending - or Unbending?
The sceptre was where I started. My hunch was that, due to the thickness of the rod, this could be straightened if I just proceeded gently... and that was the case. One slow, steady bend made the rod straight again, with a few gentle prods to knock out a slight wiggle. I know some of you were worried that the rod would be too weakened - but to my good fortune, the sceptre is still strong enough that I can lift the entire miniature by it!
Then to the crest. Again, the metal is very thick (this is a gorilla, after all). With a gentle twist, I corrected the crest to run in the right direction... but it looked wrong. Then I realized, to my horror, that I'd turned it to run fore-and-aft when it's supposed to run side-to-side! So I twisted it back the other way.
All this twisting should have considerably weakened the metal, but the crest seems solid enough.
I then used a needle file to remove the paint from the areas that needed patching. I was surprised how easily the paint came off.
Patching
I was concerned to get a good "connection" between the new paint and the metal, so I brushed on a coat of white gesso and let it dry.
The sceptre was easy, as the bent area was originally black (the part beneath the shiny area).
For the helmet, I'd been worried that I didn't have a good color match for the Nauseating Blue originally used. The idea of going with brass sounded good, but I slipped up with the gesso and touched some of the rest of the helmet, so in the end I just grabbed Ceramcoat Phthalo Blue and went at it. It took two coats until I was happy with the coverage. The color is darker, but I think that works as it looks like the crest is shading it. The finish isn't perfect - perhaps I didn't clean all of the old paint off? - but I think a sealer coat may smooth everything up.
I had planned to do some shading or highlighting if needed, but decided it looked well enough as-is. (Or, I figured to stop before my luck ran out...)