I'm bumping this thread because this was never resolved and is still a weird mystery. Sharon Soul can't be both Black and White at the same time. I think there are two possibilities here:
1. Sharon Soul is not Susan Phillips (I'm not that confident in Castle liner notes). It's possible Sharon Soul might not even be Sharon Sieger, as BMI records are wrong more often than I previously thought, but I think she probably is as "Sharon Soul" is mostly likely a pseudonym.
2. Sharon Soul, Susan Phillips, and Sharon Sieger are the same person and All Platinum used a photo of an unrelated African American woman on the Susan Phillips LP cover (sort of the inverse of what happened on 50s doowop LP covers marketed toward White audiences).
Anybody have any further opinion about the two? I would have definitely said #1 as it seems more plausible than #2, but , listening to the records, Sharon Soul sounds White and Susan Phillips sounds like she might be White. Also, to further complicate things, All Platinum really didn't care that much about proper artist credit -- for example, the Val Martin 45 is clearly Donnie Elbert on the A-side but if you get a stock copy, it's a recording of someone else on the flip.
One more thing. I'm pretty sure Susan Phillips on All Platinum 2328 ("just how long") does come as a rare stock copy with the flipside, does anyone have it? I think the flip is "he's gone" but I'm not sure.