Sovus Lock Ring for Sovos Fixed Hubs

Hello,
Are your Sovus lock rings (14947) standard sizes?
I have a wheel with an older Sovus fixed/free hub. The fixed side will take a track sprocket fine but when I attempt to put a lock ring on it is too large to screw on. This leads me to think that I'm using an older non standard hub as described by Sheldon Brown (http://www.sheldonbrown.com/sovos.html). I'm wanted to check before ordering.

Thanks,
Julian