AfaIk, the yokes for the 35mm drum-brake forks are dimensionally identical throughout the entire 750 range. Early ones were marked Arces, later Ceriani. Only difference between GT and S/SF,etc forks are the lengthened sliders of the GT type to go with the sheet metal shrouds as opposed to the rubber gaiters or dust caps.
A few GTs were fitted with gaiters...
piet