Just saw this on GI.
http://www.gunsinternational.com/detail.cfm?id=100065211&string=s=today

Very nice gun - with provenance.

I had a Mauser which was said to belong to the Johnsons as well, but alas, no proof.
When I was researching that gun, I wasn't even able to come up with a picture of Osa with a Mauser. Seems she always had a Winchester lever, or an '03 Springfield based bolt gun.