Real Spector would have been mono! The wall of sound approach gets very washed out and small sounding in stereo.
The reverb was a chamber with tape slap carefully mixed into the send. There was also lots of bleed between the mikes and bleed from the control room speakers played a distinct role. (There's a great story about how they rebuilt the studio and lost the "sound" until somebody figured out they could get it back by leaving both the studio and control room doors slightly ajar!)
Phil almost always had a Fender bass played with a pick doubling a line that was played on an acoustic bass with echo on both. This has a very distinctive sound that was at the heart of most of his productions.