Hello, I need your help to identify this steel frame. The number CO2 6867 is stamped in the bottom bracket house. The thread norm is BSA. The gear cable channels are placed on top of the bottom bracket house. Diameter of the seatpost is 26,8mm. The fork is stamped with ' Made in Japan ' and the fork dropout ends with 'shimano'. The frame has no original decals, they are overpainted.
Many thanks, hope someone can help me!!
All the best,
Gilbert Zwick
Germany