Mailbox
The company to contact regarding a mailbox is Creative Mailbox & Sign Designs.
Phone: (407) 917-7100 or 800-780-762
They can provide you with a replacement mailbox or the numbers, flag, and Georgetowne label to refurbish the mailbox yourself.
DIY Refurbishment
If the structure & integument of the mailbox is still good, the following steps will spruce it up a bit.
Using a wire brush or sand paper, remove any powder coating that may be lifting or peeling
Primer the component using either a gray Rustoleum or Krylon primer product.
Paint the component using either an Industrial Enamel Gloss Black paint that you would apply with a paint brush or a Krylon Gloss Black spray paint.
Finally, Spray some WD-40 on a Q-tip & apply to the screw @ the Flag area of the mailbox. Then tighten the screw on the flag and you've freshened up your mailbox.