Hi Sam ---
I would be worried about your coin being a counterfeit. The giant deformities in the wings, as you point out, look like severe production problems. Such problem coins would not be issued by the Italian mint.
Normally, genuine examples of this coin sell for $300 to $500 US dollars. But, if yours is a fake, the value is about zero.
To support my assertion of fakehood, I photoshopped an image of your coin next to a known genuine coin. In addition to many departures in pattern, including mis-formed lettering, the absence of denticles on your coin is a sure give-away. The database from which I extracted the image of the genuine coin has well over 50 Umberto 5 lire coins dated 1891. All of them in the database have denticles around the outside.