Two Brigade Games W.W.I chasseurs converted into Federales and one Copplestone Chinese also converted into a Federale.
For Bengal Club Wild West Shoot-outs we use the 'Rules With No Name.' These differentiate between 'cover,' as in something to hide behind, and 'rough terrain,' which merely interferes with aiming. The gents at the club interpret this as "If the figure is behind something (like a rock) then it's cover. If the figure is behind the base on which the rock is mounted, or on the base, then this interferes with shooting, but doesn't provide cover.
Consequently, there are lots of theories flying about as to what sort of bases should be used for terrain. Lately, with the movement of the music industry towards MP3's, some of us have started using CD's to base terrain.
Here's some rocks from the garden, and a bit of plaster, on a CD... With Federales of course.
And here's another angle, displaying the shape of the CD.