Here is some info on Locust I got a long time ago from another site:
Black Locust has small thorns ¼” to ½”, Honey Locust has long thorns that grow in clusters. The thorns of a honey locust tree are from 2” to 6” long. Black Locust has a thicker bark then Honey Locust. Good luck, Jim

Whatever you do, have fun doing it!