Hi thanks for the compliments, the screws are bought straight from a fixings company, over here in the uk they are called square head coach screws, i believe in the states they are called `lag screws`!? They are zinc plated, all i do is use a triangle file on its edge, and file in the v shape. You can use a sharpened chisel and put the screw in a nail header tool and forge the pattern in. This is my usual method, but i was in a rush and the fire wasn`t on!!
I used the torch to burn the plating off and just polished them up afterwards.