Here's a larger photo,
Yeah, but not by much. I have a couple of pressure regulating valves on my bus. The originals, on the bus from England, were leaking from every adjustment screw, gasket, thread, etc. I ordered a couple of new ones from Bendix, they were visually identical to the old, corroded, worn out valves. They look nothing like this.
But that's not saying that they're not a different model of regulating valves from Bendix, or an older valve from Bendix, or a regulating valve from Haldex or Meritor or another vendor. But this one is not anything like regulating valves I've seen.
Any idea where the tubes run? Is the "pinched" one cut off as part of the pinch, or is it just pinched and running somewhere else? If you can find what those tubes are connected to, it will probably tell you what the valve does.
UPDATE: There's reliable confirmation info from Paso One (who knows the exact function of that valve). My comment doesn't really help much.