Some higher-end Raleigh-built bicycles in the 1950s used aluminum alloy seatposts. They are fairly rare, but here's a decent one. It has its share of scratches and other patina, but it's the genuine article, stamped "RALEIGH INDUSTRIES." It is ten inches long.
We have numerous standard chrome seatposts for Raleighs and other English bicycles. Please contact us for details.