On Wednesday, August 9, 2017 at 6:20:52 AM UTC-5, Bojack J4 wrote:
The 18m tips on LS6c really were added to the 15m wings as an afterthought
to the formerly successful LS6 racing wing to support a self-launcher
version, which never was marketed.

Perhaps you are referring to the LS-9 motor-glider (which I have seen)?
It has a nice tailwheel-in-rudder like later Antares and ArcusM.

See ya, Dave