Hello Rob,
I don't think I can help you with the parents of Job Millership.
But the Millership's that I am looking for also come from Oldbury.
On my Great-Grandfather's (Joseph Millership) birth certificate in 1907, his father is named as John Millership a Boat-man from Oldbury. His mother is Rebecca Roberts. I haven't gone as far back as you yet, maybe the parents of Job Millership you are looking for will be amongst the Millerships that i am tracing.
I have become stuck with my Millership line at the moment and i am awaiting help from other family members.