I have small amounts of oil seeping from the large cap and it collects in the valley. Is this replaceable and replace the entire hpop?
It's not the hex plug, it's the large cover that is leaking.If you look closer, you'll probably find it's coming from the hex plug on the rear of the HPOP. Clean things well and check again. That plug has an o-ring seal that's easily replaceable. The large cap leaks a lot less often than the smaller plugs.
Your pictures do show oil on the bottom of the large cover (can't tell on the hex plug photo - too fuzzy), but the large cover is BELOW the hex plug, and gravity still works, the last time I checked. It doesn't look like you've cleaned it up recently to be sure where the oil is coming from. If you haven't done that, you don't really know the source of the oil.It's not the hex plug, it's the large cover that is leaking.