Looks like a manifold that uses 44mm carbs., and was used on couches which possibly had some low speed advantage if the carbs could communicate with one another through the crossover . (I just made that up). This crossover seems tho have been filled in for better tuning when used on a Superjet application. If the crossover is filled nice and level and the epoxy has not shrunk (only happens when first curing), you only need one gasket and may delete the aluminum plate.