’48 Crown Imperial Limousine – correct key?

I've been digging all around the internet researching the correct key for this car.........getting mixed answers. The best I can tell at ekeyblanks.com is the X1199B.

However, scrolling down info is also conflicting - fits C40 46-48, then says Crown Imperial 40-42.

I played a bonehead move and lost my keys........came back from Cars and Coffee, locked her up Sunday AM, that was the last I saw those keys - any help is greatly appreciated.

thank you.....
Author: thomasrc