I used an aluminum case, but plastic is just as good.  The board is spaced up from the bottom by the thickness of two 10-32 nuts.  I did not use a heatsink, but I do recommend using one.  Some attempt was made to keep water out.  A rubber boot will be added to the switch.  The wires and LED are sealed.  The top of the case will be sealed with silicone rubber once everything is working properly.  The tuning capacitors shown are for tuning a 4ft 4" diameter loop.  The LED wiring is correct (see note in README)