Hi thats an auto locking hub - standard on UK Frontera A series/Trooper mk2 - but unheard of on shift on the fly - i think you have got a trooper front axle fitted by someone in the past - the VX has a vacumn operated shift on the fly axle -
Well actually the US version being constant 4wd might well not have the vacumn operated SOTF part - but you certainly shouldn't have that auto hub - they are really old - my '92 Frontera has those lol
i think you need to discard and go to a breakers and get the right parts - your drive shaft should go into a solid six bolt shaft end then the circlip goes on after the shim
cheers
Steve