Sanwa Joystick Type in NEOGEO

Hi could someone please tell me what model number Sanwa joystick is inside a official NEOGEO joystick.
Basically I want to upgrade mine and need to fine a suitable replacement, so in fact if someone could tell me what others use to replace with that would be great too


Thanks

 

I think its a seimitsu not a sanwa but maybe I'm wrong.

 

its a shame these joysticks don't have model number written on them, other wise I would look at the stick itself. I will look at seimetsu ones and see if I recognise the one that I have

thanks