I don't know what a shop that normally does small stuff would charge, I just know about my brother & not much about that industry in general. His shop usually does big stuff - mainly those bus bodies for Marathon and their clients (movie stars, rock bands and such). He just does his own stuff for fun.
He was looking over my recently acquired XJ and dreaming of the possibility, but we are't even sure that valve cover is aluminum & not that die cast pot metal stuff (we are gonna pull it someday and get a better look, or maybe somebody here knows). If it is aluminum a good scrubbng with soap and water and removal of any paint would get it ready. He'd start by sanding down as much as possible with 200 grit then get after it with a rag wheel and an abrasive compound they get by the drum that I only know as green sh!t. It's not rocket science though, you could actually do it yourself at home with the compound, wheels, and a big electric grinder like welders use. Intake is for sure aluminum, and I never took notice of the fuel rail on the 4.0, but many of them are stainless. Heat shield, though probably just plain sheet steel, could also be polished to look presentable, but nickel plating would be better. My brother doesn't do plating anymore, too durn many environmental concerns these days. The government still checks test wells for nickel on a regular basis and they haven't done plating for ten years.
