Passengers are missing their heads and hats.
Dating: the four-sailor boat was produced from 1950 until at least 1953. In 1952, the "HOLGATE" on the bow began to be written in a panel in the top (thick) line, instead of below it, as is seen here, putting this example in the first two years of the four-sailor period. The sailor construction changed in 1951, to include the peg on the head, instead of the hat. We don't have either here, so it's difficult to tell which of the two years.