Welcome aboard, Paul (MIKEP).
I did some Googling and found some info for you.
From Karsten Kunibert Krüger-Kopiske
, who lets us use his drawings, the SS Cape Martin was a C-1-B brealbulk cargo ship, built by Consolidated Steel Corp., Wilmington, CA.Click here
and scroll about half way down the page.
I also found a photo.Click here