I think Eltridge was Sam (or somebody) having a bit of fun with that luscious bit of Lovecraftiana, eldritch. The bit with the letter-set that comes up in an episode or two comes straight out of Rosemary's Baby. "The name is an anagram!!" (I saw a theatrical screening of RB recently and was amused to note something I had never remarked upon before--in the world of the Witches of RB, 1966 is Year One!)
I've always thought that Erica was a drag queen who had fairly recently decided to go 24/7. Check out the movie The Queen from 1967 to get the period context for transgender culture of the late 1960s. Erica seems just a bit less "real" than Christen Jorgenson, the first public transsexual who was on a lot of talk shows in the 1960s and early 1970s. Things were a lot different back then than is the case in today's trans world.
Since Leona is a spirit who has become embodied for just a few hours through an rite of Black Magic, it makes a weird kind of sense to me to cast someone who was still in something of an in-between state in terms of gender. Even if Erica was female-born, she had an edge that made her VERY compelling in the role of Leona. I know whenever I screen this episode, I can't take my eyes off Leona whenever she's on camera.
cheers, G.
