Create shims to sit between rudder skin and rib1

These shims, made from 0.64mm 6061-T6, sit between the rudder skin and rib 1 at the first two rivet hole positions behind the spar channel. They are intended to smooth the transition from the slightly wide spar channel to the lesser rib1 width. These shims were etch-scrubbed and primed in the usual way. The shim thickness was chosen to provide a stepwise transition from the spar channel width to the rib1 width so minimising the depression of the skin.