First, Go to the web site for the Ni Institute and look up publications on seawater pumps.
In general yes, this a combination of materials that would be used in ambient temperature seawater. There are other (more modern) options.
Check if this seawater is close to some other water bodies laden with trace quantities of corrosive chemicals. Material of construction may also be influenced by choice of biocide and mode of dosing (hypochlorite or copper sulphate generator etc).