The aluminum Name and Number plate identifies the Company, place of manufacture and the Car Number (eg 45030). This is the number required for vehicle registration and must match the serial number stamped on the chassis.
You should also find a stamped, oval aluminum disc which identifies the Body Number.
Numbers on the chassis include the Chassis (top of dumb iron), Engine (on the block below carbs, but often not stamped), Gearbox (top of cover) and Rear Axle (stamped on brass filler screw).