I'm looking for a good condition, 1951 Coupe deVille windshield.
Do you have one???
Looks like 1950 thru 52 would work for you.
Also should interchange with comparable Buick, Olds & Pontiac models. Maybe Chev also.
http://www.modifiedcadillac.org/documents/Multiple_Years/46-52%20Chilton/tn/46-52%20Chilton-36.jpg.html
Have you tried any of the vendors in Otto's Cadillac Vendor List? http://www.modifiedcadillac.org/forum/index.php/topic,5742.0.html
Auto City Classic sells brand new ones For $459. Contact info is on the aforementioned "List".
Click on link below.