They are stamped 5350 B.
They are for a folding seat. This is commonly used in TT trucks,and Depot hacks .
Similar ones, show in catalog page clipping
Richard, Do you want to sell them?
Jack and Dan,
Thanks for the information. It's great to have a resource like this.
They were generally called "lazy back" seat hinges and Ford used them on early Delivery Cars but they had a different factory number so these were NOT the ones used on a Ford delivery car as near as I can tell.
In this view you can see the 'lazy back' seat hinges that John posted.
The top of the irons typically hold a narrow padded back rest. The lower irons mount to the seat base, and the hinge allows that backrest to drop down.