Success!
I started with a fresh image of OSMC. I then downloaded the RetrOSMC script, which is just a frontend for the RetroPie setup script.
I installed RetrOSMC (RetroPie) on the machine, then I downloaded and compiled the source for Attract Mode without having to install X.
Then, I copied the configuration files for attract mode from floob's image. However, the default user in OSMC is "osmc," not "pi." This broke all manner of path references in floob's stuff. So, rather than trudge through all that to change it, I just created a symlink in the /home folder that points "/home/pi" to "/home/osmc." That worked!
Then I had to fight with modifying OSMC's menus to load Attract Mode. Thankfully, I was able to grab some scripts for RetrOSMC to launch EmulationStation, and modify them to launch Attract Mode.
I am currently taking a snapshot image of this to upload to the InterWebz if people are interested. If there is any interest, I'll post it and more information that the end-user would need in order to get it set up for them.
Let me know if you want it uploaded!
CREDIT WHERE CREDIT IS DUE:
OSMC.TV: They made the OS that this is based on. Aside from tweaking a few lines of XML in the Confluence skin, It's unaltered from stock.
Floob: I would not have been able to put this together as quickly without all the work he (she?) did making their image. The basically pre-configured copy of Attract Mode made this MUCH easier. The upside to this is that if someone uses this image, they can still use Floob's video waltkthroughs to set it all up.
Mcobit: This is the guy (gal?) who wrote the scripts that launch EmulationStation out of OSMC/Kodi. Simple scripts, really, but by modifying a script that I KNOW worked, I didn't have to reinvent the wheel. I give him full credit for these scripts -- I just tweaked them a little bit.
