Here is where I am leaning after yesterday's post.
Pending any better suggestions from my players, Fine armor will work as listed on DF1, p. 27, plus chinks in armor will be targeted at an additional -1 (-9 instead of -8). When layering armor, if both layers are fine quality, the wearer does not suffer a -1 DX.*
* Note that Giant Spider Silk cloth already does this; Fine will allow "regular" cloth armor to be layered (albeit with less DR than Giant Spider Silk) as well as other flexible, concealable armor to be used without that pesky -1.
I think this will make Fine worth the cost, and a tempting way to spend money even on fairly light armor. It also makes it better for the cost compared to Lighten, too. In other words, it goes from "nice if your armor is heavy and you've got scads of cash" to "what can I make Fine and wear in combination?"