Mike,
I gave your image a quick going over, and I can't see many background Galaxies!!!!
Hahaha, fooled ya!
I spent quite a lot of time with your image enlarged 600% and I have marked the visible ones for you.
I started at 300% and wasn't sure about some of them, they looked like faint stars. But at 600% they gave spiral, side-on, and elliptical characteristics!!!
Great work mate.
Here they are. Zoom your original to 600% and you will see them all.