I have an antique teapot that is confusing me, I know that 875 but mine has 873 on it.

In addition to that there is what appears to be a 2 or a ? under the 873. There are hallmarks but they are difficult to read. Also there is what looks like XN/N and the numbers 834 etched on the bottom. Any information to lead me in the right direction will be greatly appreciated. Will try to post photos soon

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