Pinotyguy,

Why don't you contact Mr Joseph Messner.
http://www.calibres-messner.com/

Parent case is the 9,3X64 Brenneke and performance is pretty similar to 6,5X68 http://www.lima-wiederladetechnik.de/6,5-mm/6,5X63.htm/

http://www.jww.de/445,264/

Triebel http://www.triebel-guntools.de/ makes dies, reamers etc. Somewhere I have a drawing of the 6,5X63 Messner cartridge and its rimmed sibling.

Johan