This is not, strictly speaking, a hallmark as your salt and pepper shakers are electroplated, not silver. The manufacturer is, of course, Elkington & Co, a Birmingham company. Unusually for an electroplater, Elkington used a private date coding system and the “a” is their code for 1961.
Thank you I am learning as I go along in the trash they go!
Give them a bit of a polish and they’ll look fine.