Sheet Metal Question

[belairbob50]

I have 2 sheet metal panels that I purchased for a 1950 Chevrolet some time ago. Recently, I discovered that they are not for this vehicle. They have a GM parts tag attached with the part number 385483. These panels attach to either side of the radiator and to the front inner fender. The air duct hole for a Chevrolet is 4 1/4" - these have a 5 1/4" hole. That is why I am thinking they are for a larger GM vehicle like Oldsmobile. I asked this same question in the Buick Post War section as well as the Cadillac section, but with no results. In the Chevrolet parts book, this type of part is listed in group 8.153 as a skirt-panel-extension-spacer-support-shield-retainer plate-front fender part #3688519. I have attached a photo for a better description. I am looking for information as to what these might fit, or point me in the right direction as to where I should look. Thank you.