Cut the rudder skin stiffeners R-915 out from stock pieces with shears, then cut the back bevel on the bandsaw.
Used the longest stiffeners, R-915A to locate a #40 hole on the edge of a piece of 1/2" MDF cut off at a 60 deg angle. The front edge was just far enough to kiss the bandsaw blade as the MDF rode on a reversed miter gauge set to 60 deg. For each of the shorter stiffeners, indexed a hole in the stiffener to the MDF hole with a cleco, then cut the waste part of the stiffener off. (Each stiffener is one hole shorter that its neighboring stiffener below.)