Pretty sure thats the aftermarket bracket that came in a kit. I've seen them on every model Alfa. 105 series, etc.Here's a few pictures of the later style AC bracket.
These required an extended #1 exhaust stud in the head.
* These are hard to find.
The one I had came from a rotted out '78 coupe parts car I had behind my house.
View attachment 1749296
View attachment 1749297
View attachment 1749298
View attachment 1749299
The Alfetta parts books only show the bracket that goes across the head. Those are the only ones I saw on factory A/C cars.