How about this one? Early stage massive overshot on obsidian, on first attempt. And, look how clean it is, especially for obsidian!! Do you know what a hammerstone would do? I have already got collectors saying it looks authentic. And, I have archaeologists saying that the tools are as authentic as it gets. And, we didn't make up "by hook or crook" knapping. The method used can be used to make many different types of flaking, and was recorded by leading American Anthropologist Franklin Cushing, during the 19th century, after living with the Zuni, during the 19th century, around 1880. So, it is an authentically recorded technology. The overshot part is one effect that can be created with some tweaks.