> Am I missing something here or is this a reasonable approach?
Before you go having them custom-machined, might be worth asking Hunter (or
whoever made your local shop's machine) if they offer suitable cones.
Another possibility would be to use one of the adapter plates that locates
via the lug holes, and bolt a spline adapter to it. Never seen this myself,
but I've read about it.
I still think the best method is on-car balancing. That way you balance not
only the wheel and tire, but all the rotating components. Although rare, it
is possible to have a brake drum or hub be out of balance enough to cause
problems. And this also points out any problems with distorted hubs, etc.
Now that I have a wire wheel Triumph again, I should probably resume my
search for a used on-car balancer at a reasonable price.
BTW, there's a nice drawing of how to grip a center-lock wire wheel for
Either scroll down or click the "Balancing Centre Lock Wire Wheels" link.
This list supported in part by the Vintage Triumph Register