Removing helm from plate-wearing mercs?

[lymontyme]

I'm trying to figure out how to get mercenaries to display with plate armor and NO helm, ROF2 client. Texture 3 in merc_armorinfo (as created by merc_tables.sql) shows plate, but with the helm, which makes high elf mercs look like Batman. I figured this out:

Texture 4 = leather, no helm
Texture 7 = chain, no helm

Following the pattern, you might hope that 10 would be plate, no helm...but it is already hardcoded as a robe type, as are values 11-16. In-between values show no armor at all.

So now I'm tinkering with the helmtexture field. The I/O looks like it has a schema for it, but it just links to the (non-helm) texture page. I tried setting helmtexture on plate wearers to 0,1,2,3,10,254,255 - all show the helm. How do I get rid of it? I know it's possible because I have seen it done on at least one server.