Not to deviate the thread any more than it is but I like Williams FP sights on my Marlins and Marbles tangs on my Pumas both are easy to get on target as they are fully adjustable for windage and elevation. If both Remington and Ruger (can't say as mine are all JM's) have kept the mounting screws for a scope the same as JM's then the Williams just pop right on. All Williams Peeps also accept all their apertures. I have a full set of low light ones that I can use on any of my marlins in various opening sizes. The only one I had an issue with was on a Marlin 1894 SS. For whatever reason, The FP hung off the back 1/2". It would work but looked terrible. I ended up drilling a third plug hole screw and threading it (took a while to find what Marlins thread size and pitch) exactly 1/2" forward of the second. I also got a few extra plug hole SS screws from Numrich if I ever decide to remove it. The receiver would have 3 plugs instead of two but all three matching.
Just as a side note, while I was at it, I also switched the front to a fire sight and got a few extra front sight hoods, one in stainless with a cut-out for a 983 SS (I have one and checked it prior). The cutout lets the light in through the hood to really ignite the sight. Naturally, with any modifications I make, I keep the parts just in case I need to switch things back to the original configuration. The front sight hood on Marlins, simply put, suck. Where my Winchesters are nice and round, Marlins are warped. I find it a distraction so I pop them off when firing and use them only for carry and storage protection. Hence the extra hoods just in case I lose one.