OP said;"It's pretty apparent there never was a molex connector on here."
Mmmm, and where did I say it ever had a molex connector?
"what black plastic thing would you be talking about because there simply isn't one."
This is the object (black plastic item with the 5 metal prongs) I was referring to;
The action I suggested was;
"probe the prongs to see if there is 0 ohm continuity with certain of
of the empty holes where the normal power connection should sit"
A finding of continuity would tend to suggest that those prongs are associated with
the power lines of the floppy circuit board - and given their exposed position at the
back of the 5¼ floppy drv, could possibly have had something attached to them to
provide power to the floppy.
Anyway, don't worry about it.
(N.B. JayCeeBee64 , some models of Tandy computer systems fed the 3½ floppy drives
power (they used) through the 'data' cable, but I don't think any of those particular systems
powered the 5¼ floppy drives they used in any way other than through a power connector
separate from the data cable.)