please mail me for more info to put TRIGOs on your Shamrock Cobra.
I have a set in germany and may be able to get you a set of 6 point (sechskant) nuts made in cape town.
the shamrock may not have enough space from the wheel hub (jaguar) to the fender. you need about 190 mm from the fender to the disk. measure through the wheel.
dom, cape town
dominikbuss@web.de