Authenticity cannot be settled on a video call. This category covers things too varied for one checklist, which makes it the right place to say what the actual method is when no guide exists for your object.
The method, for anything
Find out what the object itself carries. Nearly everything collected has something on it — a maker's mark, an edition number, a stamp, a code, a signature. Ask for a photograph of whatever that is, in focus and square on.
Ask for the faces nobody photographs. The underside, the back, the base, the inside. A seller who has photographed only the attractive view has shown you the least informative one.
Ask what the claim rests on. If it is described as old, rare, limited or by somebody in particular — ask what that is based on. "It says so on the base" is an answer. "That is what these are" is not.
Ask the three disclosure questions. Has anything been repaired, replaced or restored? Has it been cleaned? Is everything original to the piece?
Ask where it came from. Provenance is not proof and its absence is not guilt, but how somebody talks about it tells you a great deal.
What a refusal means
Every request above is a photograph or a plain answer, and a live show is the easiest place in the world to ask for both. Reassurance offered in place of either is the pattern worth noticing, whatever the object.
What this page will not do
It will not give you tells, here least of all — the category is too broad for even a dishonest attempt. What it can tell you is that the reliable move is to turn every claim into a request for evidence, and then take that evidence to somebody who knows the specific thing.
What protects you if you get it wrong
Anything sold as something it is not is not as described: returnable for 7 days whatever the store's policy says, and a counterfeit is reportable.
Questions people ask
What if nobody online collects my kind of object?
Then the photographs and the seller's answers are all the evidence there is, and the price should reflect that.
Is a maker's mark proof?
It is evidence. Marks are copied; a photograph of one is still worth having.
How much should I ask before a small purchase?
Scale it. One disclosure question on a cheap item, all of the above on an expensive one.
More: spotting a counterfeit before you bid, Metzee's position on counterfeits, reporting a seller, questions to ask before bidding on a collectible.