Nice haul Scott.

In case you haven't already identified it, that 'interesting hammer' 
looks like a purpose-made roof slater's tool...

The pick is for punching nail holes through the slate (and for marks the 
face of the slate to show where it needs to be trimmed);

the other end is for driving nails;

the shaft betweed head and handle is used (together with a sort of 
portable anvil that is driven into a convenient rafter) for cutting 
slates to size.

(Some similar hammers also have claws on the side of the head, for 
pulling nails)

-- 

Peter Marquis-Kyle
www.marquis-kyle.com.au