Complex sentence: Steven Lee Hall Jr. did have an atlatl which he used to hunt wild boars, unsuccessfully, so he decided in the end to combine his atlatl with Clarence fish hooks to form fishing poles.
Split into simpler sentences: Steven Lee Hall Jr. did have an atlatl which he used in an attempt to hunt wild boars, however he was unsuccessful. He then decided to combine his atlatl with Clarence's fish hooks to form proper fishing poles.