I have 2 Octo TBs for my Mac and 2 Octo USB for my PC and I've never once thought about what they look like internally.
It would only make sense it's a PCI-e card but without the end piece that locks it down to the case.
When/if you do open it up, please let me know (simply for curiosity sake mind you).
Not to be pedantic, but....
(ok, I am being pedantic)
The phrase you both were looking for in the context of your writing/musings was "and who couldn't care less"
Wait..... I just remembered I have an Apple Credit Card burning a hole in my pocket (i.e. full line of credit available).
Oh yeah, my son-in-law works for Apple too. Maybe there is a decent discount to be had there.