IIRC, you're working on the USS Trathen (DD530), correct?
Hawk Graphics makes a set of 1:144 USN WWII hull numbers, draft marks, jacks, ensigns, & aircraft markings which will fill the bill.
http://www.hawk-graphics.com/
And before you ask about the lettering for the name ... during WWII the welded-on letters which spelled out the ship's name were painted over. If you absolutely have to have them, get a set of rub-on letters in the appropriate scale (IIRC they are 6 inches tall). Apply them, then overpaint with the hull color so that they just appear as subtlely raised.
You can deal with Darren Scannell of Hawk. Good fellow.