Eastern National 379,FJN163, a Bristol LS5G with ECW B41D body. It was one of a pair new in 1953 to Westcliff and in this picture it still has the Westcliff-on-Sea fleetname (and presumably the red livery) but it has gained the Eastern National fleet number.
It was later converted to B43F and in 1964 was renumbered to 1205.

Photo taken by ??? (Ian Banks collection), Southend Tylers Avenue