nether_excavator image texture doesn't exist.
vibranium_excavator model calls vibranium_hammer texture
glowstone_excavator is not able to craft

I love the mod and I'll continue testing future versions to make it as good as vanilla hammers mod is <3 .

Thanks for the report & your time; much appreciated. I just pushed a 1.0.2 release that (should?) fix these issues. ❤️