55.2-59 Air Vent Passages

[2001convertable]

I decided to change out my air vent seals. The truck had been restored and the person who did the restoration didn't replace the seals.After taking out the door on the drivers side I noticed that behind the door in the passage was not painted. I reach inside and down to see if I can feel anything and I couldn't believe it. There was a massive bunch of dirt. My vacuum couldn't get in there so I got some tubing and reduced the hose to an inch. After I thought I got it all I reached down to find more packed in. I couldn't get to it. I noticed that some of the dirt had come out the bottom of the truck in the wheel well against the driver foot area. I noticed a small plate covering a passage way but not totally. I tried to get the screw out of the bottom of the plate and it was frozen. I cut it off and bent back the plate up to expose the passage way up into the cavity where I was at

above. Well I must have gotten out about a gallon and a half of dirt and decomposed animals. Ok, heres the question of the day. Does that plate I bent up belong there and is that passage way supposed to be open of closed. Also where does the air flow for the vent come from? Does it come from the vents above the hood or some place else. Im going to attach two pictures one of the vent passage in the truck and one of the wheel well passage plate which I don't know if it belongs there. Please if anyone can answer this question that would be great. thank you