I have recently purchased a Claud Butler Olympic Road frame and forks from as far as I can gather 1969 or 1971. I've been having great fun over the last few weeks trying to track down various parts for it and it is now coming together nicely. However I am having trouble finding out the seatpost size. Even measuring it I cannot convince myself either way as the margins are so close. I bought a 27.2mm seatpost thinking that this would fit but it is too big and rather than blindly purchasing another one I thought I would enlist the help of the forum experts here in my quest not to waste any more money.
Does anyone happen to know the size of seatpost for this frame? The seemingly original sticker does seem to confirm it is Reynolds 531 plain gauge tubing.
Many thanks in advance for any help,