Despite the cancellation of the Selbstfahrlafette für 12,8cm K 43 und 15cm sFH 43 Project, Rheinmetall continued to make more vehicle proposals in the early part of 1944. These final designs shared the modified Panther chassis developed for the Skorpion. Drawing H-SKA 86187 from January 11th, 1944 was yet another proposal for mounting the 15cm sFH 18 on a Panther-based chassis. An improved version of this design came on January 31st with drawing H-SKA 88200. At some point the mounting of the gun was raised from 2,500mm to 2,750mm off the ground to allow greater elevation. Further details are unknown.
A February 20th, 1945 report on the emergency situation of the War gave a list of projects that were to be immediately terminated. On that list was a 15cm sFH 18 auf Panther Bauteilen. Whether this was the same or a different vehicle is unknown; however the odds of it being the same design are unlikely, as Rheinmetall seems to have stopped work on Panther-based weapons carriers a year earlier.