'40 brake lamp switch / master cylinder issue?

[Kube]

Okay guys, I'm getting frustrated.
Working on a '40, stock brakes.
Wiring is all good for certain.
I can get the tail lamps to light up IF I jump the two wires at the brake lamp switch.
I have power on one wire as I should have.
I have replaced the switch three times. Two nos switches and one brand new replacement.
As you guys know, when applying the brake pedal, the hydraulic force should close the switch circuit and the brake lamps should light up. Testing, there should be power to both terminals at the switch.
They don't. Not with any of the switches.
So, my way of thinking is the hydraulic pressure is not activating the switch(s).
Car stops just fine and has decent pedal.

Oh, if I jump the two leads at the switch, the brake lamps are nice and bright.
What the heck am I missing?