Quite different stocking on these two rifles, Blixen's and XAUSA's. XAUSA's stock seems thinner overall, the fore-end definitely so. And shorter in the fore-end. XAUSA, do you know from what rifle the stock came from ie a Rigby what?

The stock was the original wood on a slant box Rigby. Karen Blixen's rifle appeared to be made in the post-WW I Mauser style, while my rifle more closely resembles the pre-WW I commercial Mauser sporters.

Finding an original stock like that one is a matter of luck. In my case, bad luck was also involved, since the sister to that stock, as well as two slant box, stepped receiver ring Magnum actions of mine were in the fire which engulfed Lon's workshop. The actions survived, of course, but it remains to be seen if they can be salvaged.