I used to have awful trouble trying to balance splined hub wire wheels. The tyre bays all used a male cone which clamped on the INSIDE of the wheel centre. On the car I could see the spinner clamps on the OUTSIDE of the wheel centre using a female cone. I found an old dog-eared spinner and machined a hole through the front face so the tyre bay could use it as an adaptor between the wheel and the balancer's lock nut. Bingo! No problems ever again.
The 16 year old tyre fitters will swear blind it doesn't make a difference and only do it to humour me, but I know different and my wheels now balance perfectly.
Andy.