I wonder though if my body is ready to learn yet another set of muscle memories...haven't I confused it enough with the other million instruments I (attempt to) play?!

I'm guessing you won't find it confusing because your body relates to the accordion entirely differently than it does to pretty much all other (non-squeezebox type) instruments. Playing the accordion, to me, is an entirely different experience than playing the recorder or penny whistle, and even very different than playing the piano, so none of the muscle memories I developed playing those instruments has ever in any way interfered with the muscle memories that I develop while playing the accordion.

I think I would have more difficulty going from one squeezebox type instrument to another than I have from piano to accordion.