Wiring for SH Tele with stacked 250k/500k volume

[stevie_bees]

I've tried to find the wiring diagram for the Tono Caballo Telecaster, without any luck. I'm looking to use a standard 3-way switch into a stacked 250k/500k volume pot so that the humbucker sees the 500k pot and the single coil sees the 250k pot. Any of you wiring gurus able to help me?