Cleaned up my original housing, attempted to install the "missing parts" and to my shegrin, the machining in that port was different. The parts won't fit. Casting date on the housing with the spring and parts is 00, spring only 02. Hard to see in the pictures.

 

I was thinking that someone lost them while playing with some tools, now I'm thinking it's a factory thing. I'm guessing one piston relieves overall system pressure, the other bypasses the oil filter if it gets clogged with crap.