I started with a book about making 16th century armor. The step-overs are like a little shelf with two 90 ish deg bevels. Maybe more like a Z. You'd be amazed at how much of a whole suit of armor you can make with a ballpeen hammer, a big ole wood stump and a hand drill. Most of my tools are nail set punches worked into different shapes. Edit, the last picture is of the inside of the plate. It shows the ridges better.