i made a slab spoon mold out of wood with my router and a 1/4 inch straight bit just drawing the slab spoon on one side of a block of wood setting the depth of the bit
to half the thickness of the slab spoon and follow the lines run some chalk around the edge of the slab spoon mold i just cut and press the second block of wood together in a vice and draw a line across the two wood blocks front and back on the top side.
pull it apart draw the now matching copy and router out that the same way,put the blocks back together in the vice and drill a hole into the mold so you can fill it taper the top so the lead flows well into the mold,
now add wire across the slab area,and match the mold halfs together in the vice squeeze tightly so the wire will press into the wood
pour lead let it cool ,it smokes a little and the mold inside turns black but it works you can get about thirty slabs out before it cooks it and
only takes about 20 min to make