Never having had to balance a wire wheel..... I suspect the issue may having the correct shaped kit to grip the wheel centre in their wheel balancing machine..? As for balance weights as a m/cyclist in my yoof, I remember seeing chromed weights that fitted over the spokes and sild down to be held by the spoke nipple.... Thus my guess is it might be worth checking out m/cycle dealerships that deal in classic m/cycles if you do not want to have weights stuck to the rims of your wire wheels... also phone around the tyre fitters in your area...?
Hope you have a good outcome, if so please let us know how you get on..
