Maybe get or borrow a larger old/beater seatpost to see what fits. May not need anything further needed doing to it.
I say beater seatpost as it's likely going to get scratched. Try a 27.2 and 27. Whichever you get your hands on first. Prob got a 27.2 you can try based in E5 but I'm not around much this week or next.
Or ask for an opinion in any LBS. They'll prob have spares lying around too.
Maybe get or borrow a larger old/beater seatpost to see what fits. May not need anything further needed doing to it.
I say beater seatpost as it's likely going to get scratched. Try a 27.2 and 27. Whichever you get your hands on first. Prob got a 27.2 you can try based in E5 but I'm not around much this week or next.
Or ask for an opinion in any LBS. They'll prob have spares lying around too.