It looks to me like it might be made by P.H. Locklin & Songs from New York based on the mark on the right, and made in 1973 or later based on the mark in the middle. I'm not sure about the leaf mark though.
Welcome to Tnet and thanks for showing us this mark. It might be helpful to show the rest of the pieces. Are all the marks the same?
From the little bit I know about British hallmarks, it does not have a date mark. Nor does it have the city of Sheffield mark, which would be the symbol of the crown.
Assay Office Marks
The Sheffield Rose (formerly Crown)
Used from the inception of the Assay Office in 1773 , the Crown was the town mark of Sheffield. Because of possible confusion with the Crown mark used after 1798 as the hallmark for 18ct gold the mark was changed on January 1st 1975 for a rose which had incidentally, been used as the gold mark of Sheffield when the Assay Office there was entitled to test the mark gold after March 1st 1904. Between 1708 and 1853 the crown is often incorporated with the date letter struck on small objects." Silver Fact Sheets
I hate to say it but it's probably silverplate. It is my understanding that if it was real silver one of those hallmarks would be a lion. That is what England uses to show that an item is actually silver. I tried to find your marks but I haven't had any luck yet. Will try some more.
Note: Even if it is just silverplate it still has the potential to be valuable to collectors.
I agree about the second opinion. I've been researching this since you first posted it, and I can't find any of those hallmarks. The one in the middle looks like a fake version of the Tudor Rose.