Hoax?
Why would someone invent a casting technology that hadn’t been used elsewhere in the ancient world, for a hoax?
If I was creating a hoax, I would try to use the exact techniques already known to be used in the ancient world.
I think I saw a replica of that dragon face in last year's Chinese New Years festival in Chinatown
(No .. I have no idea if there WAS a new year's festival in Chinatown last year ... it's rhetorical)