They were avail from a lotus Le mans climax engine race cars, some jags, austin healeys and MG twin cammed GT models.

I suppose they are the grandfathers of Motorbike carbs.

The 4th pic shows perhaps a 2.25 inch and 1.5 inch and would love to get my hands on at least one to get made either by casting or CNC as they have the Weber pattern for bolt up to conventional weber manifolds.