This is Jack of St. Louis. If your intention is to return your ECO to the original way it left the factory the letters on the Model tag tells you what it included.
But, if you purchase a new ID tag, you stamp it any way you want.
Since your meter has a extension on the back of the head, something was originally there.
My assumption is that you don't have a copy of my Air Meter Identification book. If you did you could see on pages 65, 66, 67 and 68 all the ways you could order this meter.
Years ago in Indianapolis I spotted an empty service station, but the ECO Islanders were still there. On one end was a ECO like yours, off the back was a pole supporting about 12 feet of florescent lights, on the other end was just a pole holding up the lights. I am only mentioning this to infer once you put a pole on the back of your meter you can attach anything you want. This page of my website shows many of the options you have. http://petrolianacollectibles.com/eco-240%20parts.htm
I just notices you did include the Model number above. AWTNL: A, air; W, water; T, tower, NL, no light. This meant that when it left the factory, it just had a tower (the curved thing that supported the pole) which is missing from your pump. This item was offered as a reproduction years ago, but I don't know if any one is making them now. From this you just slide in a pipe, Let this pipe support anything you want. Find an original Revere light, or a pylon-florescent light, or anything you think would look great.
I have a great deal of original literature for your ECO, contact me if you are interested.