Well, shoot! Sorta.....
I ran into a bit of a "situation" when I finally went somewhere that I could shoot 50 yards. I was hitting a 1"-2" inches low at 50 yds., well centered. So I adjusted the RPP peep up a couple of turns, pretty much to max upward adjustment. The next group came up as it should've, but moved over to the left around 2".

With my particular RPP peep, when I move it up to max height, you can see the aperture move over to the the left somewhat, away from the windage adjustment screw.

Now, I like RPP products, but no way to really "lock in" the windage doesn't seem all that repeatable to me. There's supposed to be some spring tension holding the windage up against it's adjustment screw, but on mine, when I adjust to max height, the spring allows the aperture to move left, away from the windage adjustment screw. You can get new springs from RPP that might fix it, but I figured I still need a taller front sight, and wanted something both more positive and adjustable. I really believe this is more of an issue with my rifle needing a taller front sight than anything RPP did.
So, I ordered an Alaskan peep sight and a .650" tall brass front sight from Skinner. I have one on my H009G as well as my H004. All 3 rifles now share the same sight picture.The Skinner windage and vertical adjustments are a more positive lockup, and both adjustments give more range of movement(s) than the RPP does. Skinner recommended the .650" front sight, and it works well so far, at 25 yds..

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So far, I'm pretty happy with how this setup worked out, today. I was shooting from a free box of ammo my uncle gave me; some old Remington 150 grainers. Typically, I haven't had the best of luck with Remington factory loads in 3 different rifles. But these ones seemed to do okay for getting a rough sight-in job done. The first 2 shots I fired got covered up with stickers. They were well centered, about 3/4" apart, and around 3" low. I adjusted the peep up 1 & 1/2 turns, and shot one round. Good windage, and still a bit low. I adjusted the peep up another turn or two, and got this group:

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This is pretty much where I like my shots to be. I hold the top of the post at 6 o'clock (the "Pumpkin on a fence post" hold) at the bottom of the orange target center, and that's reasonably close for now. Again, after I have some cataracts fixed, I'll shoot at 100 yards and see if I'm still a Happy Boy. Will also be trying some reloads soon, again at 25 yds. for now.
I think something else that helped more than I'd realized it would is the RPP sear I put in. It brought the pull weight down from 3.5-4 lbs. to a really repeatable 3 lbs., which helps groups a good bit as we know. I don't use the reduced power spring included with the RPP sear; have idea if or how much that might reduce pull.