So, we prepped the steel panels with epoxy primer and some gray primer over that (the epoxy primer is black and we didn't want it showing through on the edges).
We stained them with a Varathane 'weathered gray' stain. HO-HUM. The test piece turned out SO much better.
The stain was too opaque to show much the figure of the maple in the sanded veneer :(
Anybody have any good suggestions? And, no, vinyl is NOT an option :P Maybe gray leather, but that is near the bottom of my list.