My mostly-original 1974 Raleigh (Carlton) Super Course Mk2 came with a birmalux alloy tube-based seatpost (and Brooks B15 saddle.) I procured a second such post for a 1974 Raleigh (Carlton) Gran Sport, from CR list member Martin Copeland (REClassicBikes@aol.com) who used to own a box of 100 NOS posts of this type.
- Don Gillies
San Diego, CA, USA