If that is the number that is stamped on the shade it is probably a manufacturers number. KF had their own part numbers for each set and there was a set for 47-50, 51-55 2 door, 4 door, coupes with no vents for the rear on business coupes plus a set for Henry J's. If you can list the length of the front and rear shade maybe someone could compare with their car and determine which set you have. They are certainly a desirable accessory.