I realize you don't think this is Gina Killmer. But, I continued to search for something to more definitively show that this is she. Here is what I have found and you can decide.
On Gina Killmer's model page on Indexxx.com one of the exact pictures you have of "the blonde in the red dress from episode 54" is shown as Gina K
http://www.indexxx.com/images/thumbs/160x181/sets/partyhardcore-ph2010-08-23-112793.jpg
Also, I looked closely at the pix you posted and larger copies of them I found on Tainster.com and Partyhardcore and various other places around the net for an identifying mark like a tattoo or mole. The blonde has a mole or make-up applied beauty mark on her forehead you can see here --
http://forum.babeid.com/attachment.php?attachmentid=370&d=1291444914
In many of the pix I found of Gina K you can see that she dyes her hair a dark color because she has very blonde roots like the aforementioned blonde in episode 54.
I did not find a pic of Gina K with the mole or beauty mark but did find many where there is a small scar in that area where it may have been removed or it may have been applied with make up for just that film.
In addition I found a scar in edge of her hair that can also be seen here --
http://forum.babeid.com/attachment.php?attachmentid=370&d=1291444914
That scar as well as another in the edge of her eyebrow can be seen here in a pic of Gina K ---
http://www.ginakillmer.com/free/02/gallery.files/p0000013.jpg
This pic ( sorry for quality, it is the largest copy of this one I could find ) of the Blonde I believe shows the scar in the edge of the eyebrow. ----
http://winimg.com/files/1398100_yfzr7/1-1-1.jpg
So, aside from her just looking like Gina K ..... her nose, chin, natural hair color, breast size and eye color..... the Blonde also has scars in the same places as Gina K .
This is enough for me to believe I found the right person to match the pictures you posted. I hope I am right Because I hate to misidentify these models.
Also, if anyone else can find a better match please, do so.
If I am wrong I would like to know who she really is too.