Thanks for the feedback nuthinfancy. I was pretty sure it wasn't the vent cause I usually check it for air release when I'm filling up. I removed the fitting at the elbow and put a light in and then a q-tip to feel for a check valve spring and found none. I then removed the elbow and found a blob of what appears to be silicone:
Based on where I found the blue blob any screens are either deteriorated or absent. My guess is that sealant from the fuel sensor broke off or dissolved over the years due to the ethanol gas and each time I top off the tank the ethanol eats away at the silicone or whatever was used as a sealant. Make sense?