​RE: Actual Z Bed Hinges?
These are a direct replacement for the factory/Westfalia hinges.  Except
they are configured to put the bed higher than the original.  And ate
complete with metal supports that attach to the forward portion of the
underside of the bed to give it support.  Who makes them?  I don't know.
The set I have is buried in my storage unit right now.  There may be some
info on the printed diagrams and instructions in the box.