Drawing of brake servo from web, will fix and upload again, to show ONE opening (mine is taped there, I assumed pin broke).
Essentialy my drawing is no different setup then links you provided, I removed the SAI but it is the same as the drawing for two reservoir setup.
Multiram WORKS in rear at over 4100 RPM, front only works when given power direclty so my drawing must be right.
I truly wish I could answer the vectra engine question. All I know an engine was purchased and installed, with only changes made to fit it right as it was horizontal on the vectra (but same Y26SE). No knowledge if ECU was replaced, but I doubt previoys mechanic would recode keys doors etc., I can take pictures or copy numbers from the ECU if it helps.
But I am wondering, doesn't V6 Vectras have multirams? and if not, why does the rear multiram works fine?
As per last page of your second link, the drawing suggests both multiram plugs share same 12V and I verified they do, and only thing I didn't check is that the negative wire for the front solenoid indeed goes to the correct ECU wire. Then again if not, how come I get the light in the dash when I unplug the front solenoid? beats me.