Hi Dan
Welcome to the forum, Looks like a striker plate or Door push / fingerplate. You would strike your vesta match on the striking plate to light your cigarette. I would say 1915 - 25. Enamel fingerplates are very popular and valuable. This unfortunately is brass or copper alloy so although interesting is quite dull lacking any colour or depth of quality. Value is difficult,. stick it on ebay but don't have too higher expectations. If you auction my guess would be £25 to £40
cheers lummox