Tim - If that eyepiece gives you around 37x, its true field of view (not "apparent") would be about 1 1/4 degrees view - too small to take in the whole nebula. With this actual f.o.v., the sky would also look a little darker, possibly causing more confusion on your part.
I have tried this nebula with my 10" newt (38x, 1.5 degree t.f.o.v.) and under very dark skies could only detect the brighter areas of the nebula. After years of trying, I tried 10x50 binos and alas, there it was on a fairly dark night. I could also detect a hint of the Pelican nebula across the dark rift from NGC7000 with averted vision.
So don't give up on it. Try the binocular approach if you can. If not you need an eyepiece with a True Field of View of 2-3 degrees minimum ( a costly eyepiece) and fairly dark sky to detect it and even then it will appear fairly faint, at best. Filters may help some but this object needs wide (true) fields of view and dark skies for fairly easy detection as a faint ghostly nebulosity with a few brighter areas. Binoculars (50mm objectives or larger) are best for these large, low surface brightness objects and 10x50 or 10x70s (to me) seem to be the best size for similar objects. Mr Q