I, for one, think someone did a home repair on the handle.
I have done that same repair myself in fact, although I of course use a standard hex nut wedged in the hole. A less reckless repair-er might use a fancy nutsert.
Whoever owned that thing prior clearly cared for it, based on condition. If it was heavily used the handle may have loosened and the prior owner decided to tighten it.
Clearly, JMHO, but I strongly suggest this handle did not precurse rivets .......