no the dots are not E & F - the sender for "47-53" is an aftermarket universal style, not as original, you might be able to adjust it somewhat by bending the float arm to suit your gauge .... sounds like the float isn't dropping as far as needed - with the tank either full or empty bend the arm a bit up or down until it reads right .... empty should be about E and full should be about F
with any new setup the best plan is to fill it and see where it reads, carry some gas with you and watch mileage compared to the reading until it runs out and see where that reads .... should be able to get 150 miles min on a tankful, so about 75 miles should show about 1/2 .... the important thing of course is to get it so the gauge reads close to E when you run out
Bill
