egafd.com

IMO iafd have Mary Brendon/Samantha Saxon wrong-way round.
On the EP37 cover SS is credited but MB is not:

To be fair the SIO cover is a little misleading.

Thanks.
But in this case I rather suspect a wrong credit in the Extrem Pervers movie.

Not only the text on the back-cover of SIO describes this girl as Samantha Saxon.
Also several performers in SIO are calling this girl "Mary" (direct sound).

Thanks, note added. I'll sort it out if/when I ever get round to
looking at the EPs.