That's a good point.  There's also 0 chance that you'd get a sale without pictures showing the object when you're talking about tens of thousands of dollars.

I would recommend locking this topic, taking your sweet time to go get some pictures of your Casascius coin, putting it back into it's secure location, then listing again with photos of the condition and proof of ownership so that you aren't putting yourself at risk.  It is great that you mentioned you are willing to accept escrow, as that will go a long way towards establishing trust with a potential buyer. 

Good luck with your sale!