Eastern National MN1221, 567CTW, Bristol LS / ECW. New in 1955, withdrawn April 1975.
At the time this photo was taken this was the oldest vehicle in the EN fleet - by contrast, the previous bus to hold fleet number 1221 was new just 6 years before in 1949 but lasted in the fleet for considerably less time.
Photo taken by Eric Thompson, Saturday 14 July 1973, Maldon Bus Station