non of the psp sticks fit exept for the psp-1000 model, the 2000,3000 vita what ever all have complete sticks where the 1000 has a nub that goes ontop of the controller, that one fits the c stick slotinteresting! maybe if I get a new3Ds someday...
One time I asked about doing something alike with the main 3DS analog and a psvita stick and they told that it's not possible ô3o idk if they differ so much lol