My friend Marinedad found this today, there was one wood screw still in one of
the holes with piece of wood still hanging on. Any idea what it is?
Found at this old tourist camp.
The type of sole plate that you found was normally used on "commercial" clubs as compared to those "pro" models sold in pro shops. Sears, Penneys, Montgomery wards, etc. all sold them as well as the major pro manufactures for their non-pro line.