Bluethunder sells a nice cast aluminum pentroof. I bought a set and they fit and look nice. They come in a as cast finish that is nice as or you can polish them. Barry R sells them and is a BT dealer.
www.survivalmotorsports.com you can see pics there. They sell both closed and vented covers. Mine are closed. Click on the B/T valve cover link...then BT images and you can see a nice closeup of the as cast finish pentroof.
G.