Thanks for the pointer. It's for personal use, not distribution.
Since I can't post on that page (
http://www.lucasforums.com/showthread.php?t=144452), I'm replying here in hopes that someone can answer. I followed the directions for "Making your newly added items upgradeable at the WorkBench." I opened my item which has Basic Clothing as the Base Item, and changed the Upgrade Level to 1. It will not stick if I save. I checked the Jedi Robe I upgraded and it is set to 0 too. I opened a bunch of other items and they are all set to 0 so I'm thinking those directions were for KotOR1, as a lot of the tutorials seem to be.
EDIT: M'kay, figured this one out, the field to set armor type, and hence upgradability, is Body Variation, not Upgrade Level. Weird thing though, while it works on 90sk's Handmaiden's Jumpsuit which is Basic Clothing type, I can't get it to work for my item which is of the same Base Item type. Still trying to figure out why a Jedi Robe can take Biorestorative Underlay and not Armorweave Underlay when they're both the same upgrade type in upgrade.2da. And still wondering what Palette ID is. Anyone?