They certainly are billet, if you read the thread it calls out very critical flaws in heat treatment that explains the large grain structure.How can those hold downs be called billet? They look cast.
Maybe I missed it, what's wrong with the stock hold downs?
I feel your pain, had to rip into mine a few times, not a nice job by any means.
Stock hold-downs are not the greatest for holding power and can stretch bolts or break/bend hold-downs (or both). While he won't be making that kind of power he wanted to take the "belt and suspenders" approach so he never had a problem in the future.