Hello! I've got a mystery road frame that I was hoping one of you gurus could shed some light on. It's a lugged frame from the 80's (I think) with the serial number SC629818 stamped on the BB. It has Nitto bars and stem, tange seiki headset, and sugino cranks. I've googled the hell out of the serial number and can't find any manufacturer that had the 'SC' prefix. Anyone have any ideas?