Steve in Stroud, Glos is looking for an I.F. transformer for his S750 radio. The one he needs is marked as 3^rd I.F. on the circuit diagram and has the part number D1535 stamped on the base plate, it’s the final 85KHZ variable bandwidth one, ( see attached picture). The secondary winding is O/C and Steve has checked the connections from the terminations of the coil to the connecting wire links and no break is visible so the failure is deep within the coil itself unfortunately. If you can help Steve contact him via e mail SteveJawor60@outlook.com