-
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.
OK, removed the bolt and teased the binding area out a bit using a flimsy plastic wallpaper scraper (I didn't want to use a screwdriver as it seems risky). It certainly looks a bit better now. Would be good to get someone to look at it, any recommendations for somewhere to take it in London? I must admit I'm wary of going to a frame builder as it doesn't seem like it will require anything significant doing. Mainly I think I need to clarify the post size and possibly get it reamed or opened out a little by someone who knows what they are doing.