1908 plates were made of separate metal panels - one for each digit, and one for the right side with the makers seal.

The last prestate plate seen is #38887 ... so potentially anything higher than that would have been issued to new registrants in 1908.
Plates with lower numbers were reissues of existing prestate numbers.

Some 5-digit plates have the first two digits on the same panel.

Here is a set of 4 plates with the same number.
The makers seals on one set have the serial number 480 ... the second set has ☆480☆
Maybe the star denotes a second set of plates (remakes) ??
Leib Brothers

This plate has an inverted "8"

Seal # 480

Seal # ☆480☆
Is the "8" inverted here too ?

Below is a 1908 plate with two seals on it.
Does that mean it was transferred to a different car mid-year ?   Perhaps we'll never know.
John Anshant

In the early days of motoring, since the actual license plate was virtually invisible at night,
there was a requirement to repeat the number in a stencilled panel which was placed in front of the headlamps.
Here are some of those panels.
They had a spring-steel wire which could easily be easily nestled into the headlamp casing.

Leib Brothers1908 Plate

Leib Brothers
Lamp Number #1

Leib Brothers
Lamp Number #2

Here is another headlamp plate.

John Willard

Here is a "man in car" picture from 1908. The plate number is 49949.