I'm beginning to think that "early" in this hobby means any pre-WWII car.
Yes, and until then I hope the backstories will outshine the build quality.
Maybe he needs it to be a Mercedes and not just a Benz.
Here's a couple more for your consideration. They don't have numbers, but they are silver.
The 40CV NM was built to demolish speed records with brute force. It became well-known in 1926 for being able to cover 50 miles (80.47 km) at an average speed of 190.013 kph (118mph). It also broke the world record at the time for covering 4167.57 km (2,589 miles) in 24 hours at an average speed of 173.649 kph (107.9mph).
The NM was a custom, single-seater variant of Renault’s large 40CV touring car.
The engine was as industrial and menacing as the car it powered. Displacing a mind-boggling 9.12 liters (556 cubic inches), the straight six was good for a mere 140 horsepower. (A contemporary 1928 Dodge Victory Six made only 52 horsepower.) Nonetheless, it was able to propel the NM to a top speed of over 120 miles per hour.
Renault NM Type 40 CV "des Records". 1926. Universal Hobbies.
The Fiat/Abarth 500 was also known as the Abarth Record Bertone. This body was fitted with different engines and color schemes in 1956 for the purpose of setting international speed records. This model represents the third engine/color iteration and brought several records with the 500 cc engine. The aluminum body was built by Bertone, designed by Scaglione, and modified by Abarth including the holes drilled in the rear to reduce air pressure.
Fiat/Abarth 500. Metro.