Brake Part Identification Help

Can anyone tell me what this is and how exactly it works? I’ve been trying to diagnose my brake issue and this thing seems suspect.
It’s some sort of proportioning valve/distribution block?
Should I toss it? Keep it?

 

Brake lock? (Doubled)

Push the brake pedal down, pull the knob. Acts similar to a parking brake.

Mico is a well known brand, as an example.

 

Brake lock was also a thought. That might be it.

The knob doesn’t really move much at all. If it is a brake lock what direction of pull would fully release the brakes?

 

Usually engagement/disengagement only occurs when the brake pedal is depressed.
Some the lever can move up or down; others could be a twisting motion.
Most require some type of lever up/down or lever in/out.

 

My guess would be push=off. Operated while pushing the pedal, as jpflat@a says.

 

I tried messing around with it while driving at low speeds today and it didn’t do anything. I think I’m going To take it apart and clean it all up and see what that does