I am not 100 % sure of the provenance on the 2 US Krags in the Amoskeag Auction converted to .405 WCF & .35 WCF.  They are from the Mark Benenson  estate.   

An elderly acquaintance, MD by by profession, was a serious hunter, trips to Africa, Canada & Alaska, etc.  He had 2 very similar Krags although IIRC both had darker finishes.  The .405 was Doc's back-up & bad weather big bear rifle.  The .35 was his wife's African antelope rifle.  I once heard her say "it will shoot all the way through an elephant sideways.  How much more power do you need?"  I shot both rifles & both worked as intended. If I needed a serious bear rifle, I would strongly consider either of the WCF rifles.

The magazines of both rifles had been reworked to allow the use of .405 & .35 WCF cartridges, which have slightly longer OALs than issue Krag cartridges.  I do not know if the rifles in MB's collection were once the ones owned by Doc & Mrs, but much of their estate has been circulating for the past 15 to 20 years.