MB, the woman who played Cal actually reminded me of Lisa Richards in Sabrina's more "out there" moments. Since Richards obviously developed considerable chops (or at least became very widely employed after her work on DS), it's possible that this other actress also went on to better things.
Tudi Wiggins did indeed play Erica Desmond on SP. In a subsequent storyline, she played another character, Helena Raleigh, and in true DS fashion, people kept mistaking Helena or actually ACCUSING her of really being Erica. It's a hoot!
We lost Tudi last year, as I think David posted. I believe cancer was to blame.
G.