gallatin - from your post, I presume your M1895 Marlin is a newer gun that isn't prepped on the upper rear left receiver wall for a side-mount receiver peep sight.
If that's the case, you still have a few options.
The first/best is either the Williams FoolProof or 5D top-mount peep that utilizes the same holes that the WGRS did, but is a LOT lower. Those two sights are lower because they carry the horizontal aperture's bar BEHIND the sight base ILO atop it, allowing an easy zero with the issue front sight.
They are the Williams FP-336 and the 5D-336, available directly from Williams or also from Midway, Brownell's ,etc. They are both W/E adjustable, the FP via screwdriver or target knobs, the 5D via sliding & grub screws.

The next option would be a specific Skinner Sights offering - the Skinner LoPro, which is basically a peep sight aperture mounted on a stem, threaded specifically to fit the scope holes atop a Marlin.
It's obviously adj for elevation , and not much windage adj should be needed since it's fixed directly above the bore C/L, but if any is needed, the front sight would need to be slightly moved.

FWIW, I've mounted my LoPro's even lower via thinning the lock ring on a grinding wheel & cold bluing.
That has to be done from the top of the ring/nut, though - since it's lower surface has a friction rubber o-ring in a machined groove that oughtn't be disturbed.
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