Thanks for your concern, jd. I tried it over again...

New blank scene, load V4.2 (only one this time), check files (V4 default skin maps in use), apply Bijou skin, check files again (only Bijou's skin maps in use), load default VSS prop, press VSS button, press VSS Synchronise, check files again: only CB Pamela's skin maps in use!

I can't imagine where it is storing the references to Pamela's skin, but it must be, somewhere, somehow....

(edit) I think I found it. There is a material stored in the VSS folder called temp.mc6. This contains references to Pamela's skin maps. I'm going to try deleting that and starting over...

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)