Antique Pennsylvania Corner Cabinet

Hello,

I have a Pennsylvania corner cupboard that was my great-great-grandmother's.  I don't know much about it, other than it seems to be in mostly original condition, including the finish and glass.  It looks like to used to have a latch/lock that was removed long ago.  I'm not sure what the wood species is; maple or something similar, as it seems light for its size.

Sorry I don't have more info, but any advice on what it may be worth or what period it's from would be appreciated.

Thanks!