Hi Tatjana,
There were a total of 628 series 7533s made in 1938. 84 of them were 7 passenger Imperial Sedans shipped CKD. This means they were shipped in pieces to be assembled elsewhere - usually overseas. Your dad's car might be one of these.
Without knowing more about the car and its current condition, value will be hard to determine.
You can get more information on your car directly from Cadillac's historical archives in the form of a
Cars Built sheet. This will tell you where the car was originally delivered and what options or special order equipment it had when it left the factory.
Click here for instructions on obtaining this information:
http://www.cadillaclasalleclub.org/authenticate.shtmlThere is a data ID plate on the firewall under the hood. If you post a photo of it here or copy the information on it, we can tell you a lot more about your car.