⭕ An ultra-early 901, genuine Solex 1964/1965 air filter housing as the photos show.
This is a very, very early 1964 housing, especially the right side is. The ultra early prototype ones did not have a flattened-off right side top housing to provide better clearance to the deck-lid. Further, the very early prototype filters did not have the internal backfire shield - the second layer of the top with the three holes in it and the slightly stepped line around the housing as can be seen on the left side.
This air filter housing is in very decent shape with minor dents, nicks and blemishes as shown.