A 1940 Chevrolet Business Coupe would have been made in 2 different deluxe models. Master Deluxe has no chrome around the windshield and no chrome on the sides of the car at the beltline. Special Deluxe does have chrome trim around the windshield glass. It also has chrome along the sides of the car at the beltline. Special Deluxe is a KA model and Master Deluxe is a KH moddel.
VIN numbers are found under the front floor mat on the passenger side, just in front of the front seat mounting bracket. The numbers on this aluminum identification plate should be something like: 6KA03 17xxx. Why don't you post the numbers/letters here on Chevy Chatter and we can decipher them for you. I would encourage you to put in the xxx's like I have in the example listed above. The world does NOT need to know your exact ID number.
Central #7A Area Director
National Judging Chairwww.1940chevrolet.com
VCCA # L 28873
VCCA #83 Tool Technical Advisor for 1937-1966