Odd aftermarket(?) crane support on Edison Standard

[Pathe Logical]

A friend has a green-oak, banner, Edison Standard model A (SN S129183) with what he assumes is an unusual crane support. He doesn't know if this is aftermarket, homemade, or an option neither of us has seen before. The item is secured on top of the bed plate (rear, left corner of the bed plate, near the rear of the gear cover) by a square nut underneath. What does he have here?

Any information/ input is appreciated,
Bob

[Jerry B.]

It looks like it was designed for a smaller horn. If you use it, please show a photo with a horn. It looks like a good idea and it's simple. Jerry B.

[JerryVan]

Homemade.