lancaster,

It's a special "Kurz" action, made only for a small batch of commercial 71/84 sporters.
Such a rifle, SN 104, appears p.25 in Jon Speed "Original Oberndorf Sporting Rifles"book.
"...a very rare half-stocked Mauser sporting rifle SN 104, with full length tubular magazine, made on special Kurz 71/84 action in calibre 11.15x37R."
mine is SN 188 and it's fully original.

DORLEAC
www.dorleac-dorleac.com