It`s a transition action.Being a former owner of this gun and having another transition action
org Oberndorf gun in 6,5x55(pictured on this forum auctions rare pre-transitional....)
my opinion 6,5 is a good choice as is 8x57i or 9x57.I personly would`nt make it stutzen
as none of the 3 transition rifles that i`ve owned had such stock though I would insisted on side panels,but why not use original stock with its patina and coppar nails.