Summary and Conclusion
Last word from Covington was that he was just about to fax me a signed copy of his verbal commitment to replace the missing piano with a new one, and that he would have an invoice or purchase order for the replacement as soon as he heard back from Bösendorfer's Vienna headquarters.
The last word from Bösendorfer (this through a US rep) was that they are involved in some kind of dispute with Covington themselves and would be unlikely to accept any new business from him at this point.
And since I tipped my hand and published these phone recordings, I assume that the charade is officially over -- the man would have to be insane to take a phone call from me now -- and so this is my last post on the subject. I will, however, publish any rebuttal or further explanation that Mr. Covington provides.
Please do scroll down and draw your own conclusions. I have tried to be fair in my characterization of events, although I have to admit that I wasn't quite as charitable here toward Mr. Covington as I was on the since-deleted PianoWorld thread.