[lousyflyer]

You came to the right place to look for a repair panel, but unfortunately you are about three days too late for me to help you. I just cut up and scrapped a cab.

Nobody makes a patch panel for the vent area on the trucks, but there are plenty of these things parked everywhere. Forum members hack them up regularly.

Judging by the extent of your rust-through, I suspect that there may be more corrosion behind it. The boxed in area behind the vent opening has a tendency to fill with water and rust out the lowest corner.

I suggest closing off the floor vent with a piece of flat sheet and drive on!