If you are thinking of building a LF camera, please see the link for info on a 4x5 Graflok/5x7 spring back system. If you happen to know the manufacturer, I'd appreciate that info.
It's Sinar Norma kit. The pieces are a 8x10 to 5x7 reducer; a 5x7 back and ground glass assembly; a 5x7 to 4x5 reducer; and a 4x5 ground glass assembly.
PS: you have part of the 4x5 gg assembly still attached to the 5x7 to 4x5 reducing back. If you are going to sell these, it would be worth splitting them up into individual sales, and re-uniting the pieces of the 4x5 back.