For someone as qualified as you, is replacing the switch that difficult?
Pull it out and take it to the local NAPA auto parts store. Alternatively, why not call the Kirkham's and ask them to ship you one?
Seems simple to me.
Your last option is to sell the Kirkham. Too much of a maintenance nightmare with all that powdercoating parts, new Vintage wheels and GYBB's, brushing the exterior and replacing hydraulic brake switches.
