Hi Milton,
according to Badrocke/Gunston's 'Lockheed Aircraft Cutaways', "Wing wake turbulence was cured by extending the wing trailing edge slightly behind the flaps and raising the tailplane above the rear fuselage." There is, however, no cutaway of the L-18, but a picture (p. 23) shows the lower side of a PV-2. The four flap segements run beween guides that extend slightly behind the trailing edge.
The two inner flap segments are overlapped by the wing's trailing edge by around 30% of the flpa's longitudinal length, but this tapers down to zero over the outer two segments. The trailing edge of the flap is a straight line with the trailing edge of the aileron.
The aircraft in question is preserved by the Confederate Air Force.
Best regards,
Volker