Identify Silver

Hi Ihave several pieces of silver cutlery i.e. fish knives & forks large ladle,serving spoon,2table spoons ,2 toddy ladles and a carving knife and fork. I have identified these as being Dutch Silver by the maker GERO ROESTVRIJ Hallmarked with E and 90 in a circle.
Can you let me know if this is solid silver and if there is any value in the pieces