The important information comes off the door post serial number tag & the two body tags (one serial number, one larger with more info) on the firewall. Many American states used the engine ID number on the block tag for vehicle registration purposes. Unlike many European countries, registration info is worthless for tracking car information since the factory records went to the land fill in the early 1970's or were burned in a 1955 fire in the basement of the building they were stored in.
From the info off the door post and firewall tags, you can tell original color, original interior, original transmission type, factory installed options, and other information of interest. We can even tell the month and year the car came off the assembly line through the end of the 1952 model year.