Let's make a template to route the driver recesses.
I've already marked one center.Tip:
If you'd rather avoid dividing fractions because you're in a hurry, just angle the ruler so you land on a whole number at the edge and divide that in half.
I could use any whole number, but for this illustration I used 20".
The vertical center is at 10", even though the board is 16 5/8" wide. Nice and easy.
Driver recess template.
Now let's make an insert ring for routing the driver through hole.
We can use the larger recess
template to make through holes on the box.
Secure the template.
Remove some waste. This will make routing easier.