Hi. As above really. The bike in question is a 93 Hahanna. I thought all 90s steel Konas had 27mm seatposts, but the seatpost I have in that diameter definitely doesn't fit.
Thanks. A seatpost is the final piece of the puzzle. I'd measure the I/D of the seat tube but as the slot in the top of it looks to be crimped together slightly, results would be inaccurate.
Just been to the shed to check out my wife's Hahanna. It currently has a shimmed post with a 26.6mm OD. Just to be sure, I removed the shim and tried spare 26.6 and 26.8 posts. It's definitely 26.6mm