Eastern National JN8567, a Bristol JO5G with Eastern Counties B35R body, new in 1937, seen here in Broadway Market, Southend about to leave on route 12 to Creeksea. JN8567 was new to Westcliff-on-Sea Motor Services and like the rest of the fleet, it passed to Eastern National in 1955, gaining the fleet number 248 and lasting until around 1958/9.
Since Westcliff did not use fleet numbers, this photo must have been taken after the ENOC takeover but before it was repainted green.

Photo from the Essex Bus Enthusiasts Group collection, courtesy Chris Stewart, taken c. 1955/6, Southend Victoria Circus, Broadway Market