Dear Bob, This frame would have been built for Simplex derailleurs. The Juy 57 front was operated by a double lever (band - on hence the stop pin.Special braze ons were also available.) The cables ran parallel down to the guide . The operating arm worked on a torsion cam principle rather like the old Cyclos. The rear would have been a conventional der,. Do you have a fax number, then I can send you images - I got them courtesy of Hilary. The Scot name would have been done like that because the lever and twin cables would have obscured the "Flying" bit, I s'pose. Mark Stevens London