I use Williams peeps on all my marlins. Thing with the FPs on the 1894 is that (unless they have changed), the peep hangs off the rear. It didn't effect function but it simply bugged me. None of the others hung off so I ended up drilling a third mounting hole exactly 1/2 inch forward of the second. I used the same tap size as the original two and ordered a few Marlin plug screws in stainless from Numrich to match the originals if I ever take it off. I was very cautious about drilling too deep and entering the chamber. I also added the firesight front sight so while getting the screws I got a a front sight hood in stainless for a 983S. I have the 983S and the hood has a cut out on top. I wanted that for the firesight though I normally pop the hoods off when firing. Thing about all marlin hoods is they are always lopsided, which bugs me. Winchesters are always perfectly round.
Anyway the center is a Marlin 1894SS. I've others but top down is a 1895 in 45/70, 336C 30-30, 1894SS in 44mag/44spec, Rossi Puma in357/38 special and a Marlin Golden 39A in 22. All the Marlins are JM, bullseyed and have Williams peeps. The Rossi has a Marbles tang.
I also have all the low light apertures but I usually use the smallest.