I made a rough sketch on this new cut section.  Now I don't intend to follow the lines but only want to give this texture a kind of swirl. Notice the straight bar behind the sheet?  Well that's used to hold the sheet in place because once I start using the pneumatic tools on this piece it wants to jump around all over the place.  I'll be using the more powerful hammer so I'll be guiding the tool bit up towards that backing bar as best I can. Normally when I use these tools for incising work on iron sheet or bar stock I clamp the work down, but even so, the clamps usually work loose due to the vibration.  Some day I'll have to figure out a better hold down device.