you are right when you say always to look at the context. I always try and searching in statistik, knowlegement of materials, photos etc etc.
the nips on the studs are not the problem. i know about the differnt way of prodcing them. And i know that there were made today in the same way...no chance to recognize.
the stud i the former pic is from an older not well done fake. but this studs can be found on serveral fakes.
the nip isn�t the problem... the wohle "lense" form ist the point of kritik. No original i�ve ever seen or own has this stud. This studs are coming with the first wave of fakes.