Technical Please help identify this garnish molding

I have spent several hrs on the computer and looking in books, trying to ID this garnish molding. To no avail. Please let me know if you recognize it. Here are some clues.
I got the window and regulator with it. The regulator slides the window back and forward. The glass has SAFETY PLATE GLASS, P 38, and LOF on a diagonal in a shield. No part numbers anywhere.
The last photo shows the measurements.
Vincent

 

general motors 1939 - 1948 would be where I would start looking.

 

Right rear window, haha
It could be from a 4 dr or a coupe. In the late 30's, a few 4dr had the rear door post leaning forward, such as 38 Hupmobile, 37-39 Nash, 36-up Lincoln. For a coupe it could be any of the Olds, Pont, Buick, Cad, Lasalle 37-up, 37-up Mopar. Could be 40's too, I don't have a book with all the 40's.

 

Could be made of metal too....
I don't want sound ungratefull but, any real info.

 

'39-'40 GM coupe, probably "A" body ... the slider notch shows it was upper $$ body.

 

Thank you. I was thinking late 30s early 40s GM. Can anyone confirm this?
Coupe? Sedan?

 

Anyone else?

 

Could be 39-40 Buick 4dr (from a google image search):