I'm betting I did it wrong, but eh. And also, I noticed I forgot to register the render for the armor in the ModArmor class, but no, that wasn't it either, if you were thinking it might have been.
(I'm still rather new to coding in general, so yeah... mostly been following tutorials and frankensteining most of the code I get, building my understanding that way, which works well enough for me, until I hit a roadblock like this :/)