Just picked up a very tall frame Nishiki Sport that obviously has seen some upgrades. No serial number on bottom bracket, but driveside dropout is stamped G0783, and the offside dropout is stamped 3187136. It has many Shimano 105 components (brake levers, downtube shifters, hubs, derailleurs, crankset with Biopoace rings, 7-spd rear cluster.) and Shimano 600 brakes. Rims are Matrix Titan.