26.6 seat post
I need a seat post for a 1980s Nishiki Olympic 12. My guess is 26.6 based on Sheldon and a quick measure with old calipers. rider quality is fine.
my good calipers are hiding. If you have seen them, tell them to come home and I will give them a better battery and put them in their case.
I have some random stuff for trade, or will purchase. Let me know what ya need and maybe we can both win.