I like your decal ideas. Another thought on the engine cooling idea. It was very common and inexpensive to just put a stack of washers or a spacer of some sort between the engine cover and the top hinge, but another method of that time was an after market fiberglass air foil that mounted between the bottom of the rear window and the top of the engine cover. This directed the air flow coming over the roof into the air intakes located in that area. I had a '67 Type 1 Baja Buggy in the early 70's that had the whole fiberglass fenders, front hood and the headlight area along with this type of intake. The Empi Wheels that I used were the solid centers that look very much like a Centerline Wheel only it was all steel. Just addition thoughts. Are you going to make your decals available at a later date ??