Hi Tom,
Thank you for the pictures and response. Like they say "A pictures worth a thousand words". Sure has helped me understand the air vent. I have the door with the clip but unfortunately I don't appear to have the piece that goes into the opening. I will have to try and make one up.
On the inside door handle I assumed there was some sort pull handle other than the one on the sill.
By now I should know not to assume anything when it comes to a 90 year old car.
Thanks again, your response has help tremendously.
Where Are You From? Kamloops BC Canada
Do You own a car built by Durant? 1926 Star (being restored to a delivery service van)
When I was taking the pictures, I first looked in the passenger side and the stairstep wasn't there so I was thinking that the vent door was just held up by friction. Fortunately, I looked at the driver's side and found the stairstep! Also on the door I presume that there was originally a strap the stopped the door from opening up too far. I don't have anything on my doors and am not sure what they would have looked like.