Hello,
I have 10 of these silver denars from Hungary under Sigismund’s reign but they vary in sizes (none of the smaller ones have their designs intact so I guess that may explain the whole thing, though). Are they all the same coin of the same type?
Yes, these are all the same coin. These were hammered by hand and it's common for them to vary in size and weight.
You'll probably be able to identify a few different mint marks on them. Check the coin's numista page for different mint marks.
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