Hey Chev,
My understanding of the Interstate front end:
The pods divert the air that pass through the radiator out past your legs into the passing air stream.
The lower underside of the engine guards, on an Interstate, have the scoops your looking for as well as small supports for the Pods. I have never had 'hot feet', but I have been very hot a few times. I guess the reality is we are sitting atop a running 6cyl engine; and they can get really warm.

I had an experience this last May, leaving Cedar City heading for Nevada, we had to go over one high pass after another. Over the first pass we ran into 3" deep slush. The scoops helped to cause my feet to become caked in ice and very wet the second I would leave the rut in front of me. Needless to say, wet feet were the least of my worries, it was some very scary riding for about a 2 miles as we passed over the submit. So I gotta believe they are doing the right thing to keep your feet cooler in ALL conditions;rain, heat and snow!
Should not be too hard to fabricate, good luck.
Glenn