Step 2.  Machine the Rear Panel

The layout of the rear panel is not at all critical except for the position of the 0.171" diameter hole for the programming LED.  You can place the power, scale, and aux connectors wherever you like.  Just be careful to stay away from the standoffs that are on the inside.  The following figure shows the layout I used if you are looking for ideas.

DRO-350 Rear Panel Drawing (Click for PDF)