Nice find, Doug. There were certainly changes in skins that are interesting, but perhaps like Monty, my impression is that the original bracing pattern remained consistent with the B-24. In pictures like these I can typically pick out a 1/2 dozen or so areas that 'look like' 2-2-V-1 by pattern, but now having touched one considerably I realize not even close.
That said, it'd be nice to be able to see a surviving C-87 up close to look for the delta between that model and the '24 to see if any fresh candidates could emerge.
One other likely negative for this being part of a C-87, in my view at least, is that 2-2-V-1 bears so many earmarks of truly expedited field work. Could be wrong of course, but not quite the same as the more formal type of work that we see in these pictures, which appears to be more 'factory kitted' to me - except for that odd set of 'patchwork' I see on the bare nose othe C-87 that is juxtaposed against the same portion of a B-24. I don't think the patterns would bear out if examined closely, but there is some interesting quilt work on that example, for sure.
It is hard to say for sure, but the interior surfaces of some of the kitwork - including for instance the bomb bay skin and frames, appears to be painted. Maybe others have a keener eye to tell for sure.
Thanks for sharing this, interesting stuff!