Yes, you can tell which specific typewriter was used to type something so long as there is either a slight defect (for lack of a better term) if two letters are closer to/further from each other or a letter is a little higher/lower than it normally is.
PLUS, because different people hit the keys with different amounts of force, each machine wears out at different rates and so the keys wear out at different speeds, so there’ll be different wear patterns to the keys.
I have never bought anything from Amazon and I don’t plan on it. I do understand that sometimes it’s the only place to find something that a person might NEED though - and at a price they can afford, so I don’t hate on the people on tight budgets that can’t find an item anywhere else. (It’s like when people buy stuff from Walmart, Target, etc. sometimes it’s the only place where you can get necessities.) However, if you can afford to get it somewhere else then do it…or if you can only find it on Amazon maybe reassess if you ACTUALLY need it.