Just in case anyone is interested... I followed up on the leads from this thread (thank you), watched and followed up on some other threads, and called several dealers who had inventory listed in AutoTrader.
None of them turned up an available truck.
I'm confident it's possible, given enough time and persistence and location flexibility, to find an available truck that some buyer cancelled on at MSRP.
But I didn't find one, and don't have the kind of time needed to invest in the process.
#raptoracquisitionfail
Thank you again for your help.