Yep.
For some reason, people are terrified to open starters and alternators. Hey-- Autozone loves you!
I can't tell you how many of those parts house units I've pulled apart (Car won't start? Replace the starter! Wait! Still won't start! Take it to Duke!)
Anyway--
I can't tell you how many I've pulled apart, only to find that this "remanufactured" unit is pretty much a pile of used components with new brushes and bushings in a new or cleaned-and-painted case. It's really kind of funny. As a rule of thumb: If they want a core with your unit, the one you're getting is not really "new."
And yeah--
I did DC electrical work for a long time. Started out of necessity as a farm boy, and eventually ended up falling back on it proffesionally after I got my spine crushed. Don't get me wrong-- it's extremely detail-oriented, and does require a small amount of specialized knowledge and equipment (I originally wrote that to be super-simplified, and included testing methods that are essentially "Fool proof" and can be done with stuff most people already own), but so long as you pay attention to the details, it's a snap
have fun with it!