I have confirmed they are genuine. and would you believe my wheel refurbing cousin showed up tonight who said (looking at some other photos too) the buckle is safe as it is but also repairable.
Glad to hear they are relatively easy to get hold of though incase of emergency.
I have a set of Advan 'Model 6' alloy wheels for sale. No point googling them as they are so rare that no one wants them because there's never any for sale in this country. Sitting in my shed doing nothing now