Hi John,
Welcome to the forum.
A friend and myself did a LEJOG in a Swallow bodied seven, no hood!!, never again
BTW, looking at some of equipment necessary to put nice louvres into metal, you need to make machines with deep throats and the tooling can be expensive too, depending the length you want them, for the amount you might want to do it might be more cost effective for someone to do them for you, just my thoughts.
Post some pics of your project, would great to see how far you've got.
From somewhere close to the Blackcountry.