I like the fab work. It's nice when modifications look like they belong there. The allowance for the linkage is thinking ahead. Prevents a second iteration on the fab. Once the linkage is sorted I would bolt the carb to the adapter and trace around the base with a sharpie. You should be able to lose the excess metal from the adapter and make it look like the manifold was cast as as a two barrel.
If you decide to go for headers - a heat plate can always be added.
