Your pump plate is good.
Here are three pump plates.Te one on the left is a repro and is dated 5-21-90 with Made in U.S.A. on the left side, which is larger then the other two signs. It has brass grommets. With no gaps on the back. It has a clean bright white back. It has a black outline to the T instead of white.
The middle sign has Made in U.S.A. on the left side in smaller and tighter together lettering and is dated 3-1-57 on the right on the right. It has a green back and a white outlined T. The grommets are steal and have a wide flare on the back.
The sign to the far right has the date of 3-40 on the left and Made in U.S.A. on the right. Again white outlined T and steel grommets but a tight flare to them on the back. A paler white backside.
When you look closer you will see many more differences in the signs. The main one I notice is that the eagle has black highlights in the reproduction sign, the two originals have brown highlights.
There are also a few other repros's out there but they are easy to spot because they are tin and different sizes and poor quality.