How to make a LEAD HAMMER MOLD from Tubalcain or MrPete222

I am trying a different attempt to make a lead hammer mold.
The halfs are machined out of 50mm Aluminium bar stock.

[mrpete]

Very nice job---and you did it in 1/10 the time it took me. I'm really impressed.

[pinselplins]

so easy can it be, without to build a complex mold ;) 
I like the Germans ;)