In Auto-Motor-Sport they say the new frame is quite possible from Aston Martin:
this rumour has been doing the rounds: it is false. AM wanted to sell the Vanquish chassis, but the asking price was far too high: one figure I heard was "over £25m" for the IP, machinery, etc.
Apparently the sale for $26m is documented in Aston Martin's accounts as part of their recent IPO.
So the sale is true but as far as I know the identity of the buyer is still a mystery.