Help with a Vintage Direct Connection Part – Proportioning Valve

[Floyd]

Does anyone have access to a late-80s/early-90s Direct Connection Catalog?   I am trying to find information on a NOS Direct Connection adjustable proportion valve that I have (Part Number P4120999).  I found a couple general references via google searches but would like to know more details about the application and specifications.  Thanks for any assistance!

[Mr Cuda]

I have several of those on cars. And a couple to use still.
 I couldn't find a DC book with them in it, but my brake handbook shows this.
DC sold a kelsey hayes product.

[Floyd]

Awesome, thanks!!