Thanks for your input! It seems this should fix it, but I'm not getting any results with the script - I select the vertex, run the script, but then nothing happens?
There's a script called mhCopyVertexNormals.mel I use for stuff like this. Unfortunately, you need to copy/paste vert normals one pair at a time, so it's a bit laborious. Easiest wasy to do it is to move the head up in Y a tiny bit, so you can more easily select individual verts. After you're done, move it back down. Grab…
Run the script first. It should give you a little window with two buttons in it, one for copying and one for pasting. The window remains open until you close it for easier use.