Your in for a lot of work !
I don't have the original intake (your lucky) I polished my original type cobra oval air cleaner. The pits in the casting were so bad, I kept on sanding & sanding then gave up. I ended up having it ceramic coated. I
bought a industrial polishing machine (like a bench grinder), burs, various sanding drums, polishes ect....and went to town on most of my alum. parts on my engine. Other than the air cleaner cover, most parts were fine. It just takes a lot of time, tools and sore fingers. Oh,..........and extremely dirty. Your shop/garage,clothes, and entire body will be filthy ! I ended up using my gas leaf blower to clean my shop. The results are rewarding and shinny though. Good aluminum like on our sprint car's suspension were very...easy to polish and looks like chrome but, it's not cast like intakes. I still have the tops of my valve covers to do this winter but they will be easy. The more sand paper grits you use before polishing the better. The intakes are hard to do because theirs so many tight areas to get into. Have any questions, feel free to email me.
