@george1421 So, I am an idiot.
What was happening here is I deployed the old BIOS image, which blew away the GPT designation, and then when I created and captured the new image, the Windows installer never re-applied the GPT. I manually went in with diskpart, wiped the drive, applied GPT, rebuilt the image, captured, deployed, and voila! It boots now.
Jokes on me for trusting the Windows installer I guess. 
Thanks for your input George! It actually helped a lot.