I think it is 6E96860 with the C being an incomplete 0. Which means it's probably a 1986 model. Offhand, I don't recall seeing an Nishiki tandems in my literature. I'll have to doublecheck. Given the small market for tandems, Kawamura proably subcontracted production, which would explain the different serial number format. I'm sure the Nishiki fans who follow this thread will be anxiously awaiting more pics.