Farmer, my apologies, you have good eyes, you were partially correct. I cannot see very well without glasses, which i did not have on at removal of filter, or taking the pics. Today I used a magnifying glass to see if i could retrieve a part number if there was one, and realized that what i though was a discolored end cap from varnish was in fact missing. What i was perceiving with my bad vision was the cardboard type end cap glued to the filter pleats, and after looking at a new one seen how the metal end cap is same size shape of the cardboard end. Apparently my son has/had removed the bowl to remove the water that accumulates and threw out the cap not noticing it, since he threw the fuel water mix onto tree stump suckers to kill them. That is our best assumption anyway. The other end cap is still intact, as that is what holds it onto the filter body/housing. I also found out the last filter my son put on is one he found in his father in laws shop, which is an inferior brand obviously (he said it was in a red white and blue box) whatever that brand is. lol But definitely not the wix i normally keep in my shop for our john deeres. I looked inside those and they do not have a hole in the cardboard, so even if the metal cap comes off, it wouldn't draw unfiltered fuel.As i said before, i just hope the life of the injection pump will not be compromised. Thank for the catch, my mind is relived of the 'why'.