That does look much like a wild callery pear. I suspect its either that or hawthorne. What its not is BET , Harbin, domestic wild pear, bartlett , pear rootstock etc. . I would like additional pictures of the trunk base and more pictures of shoots. The encouraging picture is this one with the thorn
Grey small spots on the bark are good also. Take a look at this thread Wild callery pear rootstocks . Look for red leaves at the base or on the tree , small dried up pear sized fruit etc. See these thorns from the thread are wild callery thorns which are variable in severity
Thank you!
