Your spoon is electroplated nickel silver and was made by Barker Brothers in Birmingham, England, between 1900 - 1960.
The base metal is usually indicated in code on the piece: EPNS means: Electroplate on Nickel Silver
Not sure about the 3 stars or Bs, those are a maker's mark I am unfamiliar with. EPNS is electro-plated nickel silver (the alloy the spoon is made of).
Electro-Plated Nickel Silver. The 3 stars and B's are makers marks. Your item most likely comes from early 20th century England. FYI British sterling is generally hallmarked with the cartouche symbol of a rampant lion. www.silvercollection.it