I have three LF backs that I'd like to ID if possible. They are all 14-11/16" square. They do not attach to a camera via pins like Deardorff or B&J, so they must lock on similar to a Century, or clasp like a Gandolfi I am assuming. The size is different than my Century Master, however.
The backs are:
Again, they are all just under 14-3/4" square outside.
Would like to know what camera they are for.