https://www.skinnerinc.com/search.php?start=0&limit=30&view=30&op=search&display=list&s=Weathervane

Excellent !! I would have been skeptical under other circumstances !! This one looks totally correct with proper aging and patina of the metal and follows the form of others of the same period !! Here are some past sale results at auction !! The only beaver weathervane that I saw recently was a carved wooden one so that price would not be typical of yours !! You also have the directional and that helps !! Yours looks like copper and has the correct verdigris for the age !! My advice would be to contact a good auction house for a proper valuation !! These can sell for several thousand or as you will see from the link a few hundred !! No way I can place a value without a hands on look !! Please come back and update this post when you have it properly appraised !! Would love to know the results !!
One more thing,,looking at how this is made,,could possibly be earlier than 1890`s !!