I believe FFC did a divorced Toyota case in the Amigo, don't know where the front section came from though.
IIRC they used an actual Toyota divorced case. What the OP is inquiring on, is a plate to mount to the front of a non-divorced case, to make it a divorced case.
Look into Inchworm, they had some of OTT adapters listed a couple years ago. They might still have one.
Here is a link to somebody modifying a dual case adapter to do what your looking for.
http://www.zukikrawlers.com/showthread.php?p=484766
