I actually would not be surprised if the insurers reject this...

I actually would not be surprised if the insurers reject this claim. Having had some experience in the jewelery trade, I know that they place a limit on the value of merchandise which can be displayed at any time, and all valuable items must be removed from display at night. It follows that there would be conditions placed on the on-site storage of MUS rubies, and overnight storage of $200,000 plus in a moveable safe does not sound compliant to me. All IMO.