I love this question and split it out of another thread where someone inquired whether a capsule he showed had original diaphragms.
NO internet authentication tutorial for vintage microphones exists, and the few technical compendiums or picture aggregations on line are often unnecessarily esoteric, or lacking in detail, or unreliable because of errors and inaccuracies.
As of late, the internet is increasingly regarded as the ultimate knowledge base. But it is in essence void of an authoritative filter that lets you and me know what information is accurate or valuable, or what statements are plain garbage, no matter how convincingly posted.
I recently had an intense conversation with a small studio owner who asked me: What is the best way of selecting the right microphone for a specific application?
My answer: sign up as an intern in a commercial studio or negotiate a mentoring program with a respected audio professional.
My hypothesis: we are hard-wired for learning specialised skills most efficiently through direct observation and face-to-face, experiential interaction with a mentor in a long-term relationship.
Accumulating knowledge in other ways is helpful and often essential, but the ability to distinguish with some certainty which part of that accumulated knowledge is applicable, actionable, and therefore authoritative in a specific circumstance can be learned best from being in the same room with a knowledgeable person for an extended period of time.
This suggestion will of course not yield many takers, because, aside of the logistical problems connecting with mentors in a globally spread-out "village", we now expect instant and accurate learning through the internet, at no personal sacrifice or cost. But history has shown that the best way to pass on the knowledge of the masters is through personal interaction with them.