Scamp uses a pair of offset chest hinges. One side is shown in this photo.
Scamp based their design on the
Boler, but I don't know if they are similar enough for this to work for you. Seems like the offset hinges would be easier to work with and just as secure. There is minimal stress on the hinge, since the ledge carries the
weight, and the hinge just prevents it from sliding off the ledge.
If you can't find them locally,
Scamp stocks them in their parts store.
https://www.scamptrailers.com/produc...f-chest-hinges