I managed to almost finish the pivot bolts. I don't have a U.S. standard NPT 1/8 tap for the zerk grease fittings so I used a 1/8 BSP tap - I will lose points at the concourse but I will say its a field fix
1/8 BSP zerk fittings are available at most auto shops here.
The dividing head I made myself to Harold Hall's design. Harold has had many books published and he is the doyen of the hobby engineering scene , he must be getting close to 90 these days .
I have a 48 tooth gear on the dividing head. To machine the bolt head flats you divide 48 by 6 = 8 notches for each flat.