I have had my '32 since 1969 and cannot remember ever seeing the setup you are talking about. Of course, that doesn't mean that they are not out there.
Here's one I have: a dual carb intake for single throat Winfield carbs - a pre-war ORD. Probably not quite what you were looking for though. Seems I have seen pictures of an early flathead intake set up for dual Detroit Lubricator carbs, but don't remember the make.
I know this is not exactly what you were talking about, but it is neat. Its a dual single throat for a V8-60. It's on e-prey and here is the item number. 250721660346 Joe