I should update this as I bought one of the mounts... it works well with regular lenses, built well... however, it does NOT work with anamorphic lenses. The pin is off and the lenses mount almost on a 30 degree angle. I went back to the rental house almost mad at them for giving me, what I thought, were bad lenses mounts but I checked them on a RED PL mount and they were perfectly lined up. Back on mine? Off to the side again. If you want anamorphic, this PL mount is useless... I might actually sell mine, if anyone's interested.
The pictures at the bottom of the Ebay page look like the key pin is in the right place - certainly no where close to being 30degrees off!
http://www.ebay.com/itm/Arri-PL-to-...450?pt=LH_DefaultDomain_0&hash=item3ccc0b6c52
Hard to see how they could get this wrong. 90degrees I could believe as I suppose the front could be mounted 90degrees rotated with respect to the rear plate by accident.