If I were to redo the L-13 wing,first thing would be to remove the
forward
sweep and use a strait leading edge with the taper on the trailing edge.
And leave off the wingtip torpedo's,maybe have 45degree winglet's
instead.

Pretty sure the forward sweep is a C/G thing, useful cockpit load and
all... also takes the place of washout, but the C/G thing is more of
a challenge to design around. Agreed on the topedos though. If someone
made a decent composite wing for the L-13, it really should work well.
Plain flaps instead of complicated/ineffective fowlers, and simple
Horner tips...

-paul