Those look like they would clean up very well. With plated hardware and a vapor hone. 🙈

I think there are rubber isolators between the carb and the manifold, check them out and make sure there are no leaks.

Nothing stands out too much, make sure the head/manifold gasket is not restricting airflow.

I have an original SK airbox for those.  Nos. It's funky and a rectangle, but if you interested pm me.  

pm sent