Dylan, that was a very good description of the differences you posted. There is another more specific(?) way to distinquish the difference.
There are two differences at the anal vent. On the male, toward the rear of the anal vent, there is a protuberance, on the female, there is a slight indentation. I have some drawings and pictures showing the difference which a found in the IF magazine some years ago, I tried finding it in my reference library, with no success so far, but I'll keep looking, soon as I find it, I'll post them.