I have seen SCAR-AR stock adapters, for airsoft.
http://yzh.hk/en_ArticleShow.asp?ArticleID=6243
Don't ask me where to get it... I have no idea.
It is not foldable, so no hinges. That may makes the wiring simpler, as the pervious wiring uses the hinges as contact, you can now directly connect with wires - if the space allows.
It may or may not be designed for VFC, but I think it could at least fit on a VFC with some modification.
The buffer tube may fit a stick battery in, but not sure if it have space for wire to pass into the buffer tube through the adapter.