Let’s be honest about what that rifle was, and what it is - the JC Higgins versions sold at Sears were affordable, high volume “every man’s rifles”. They’re not artistic works of gun craft, even in the Marlin iteration, let alone the JC 45’s. Today, it’s just an old rifle, not a fine antique rifle, not a collectors’ rifle, just an old rifle. It’s not a pre-1900’s or turn of the century rifle, it’s just an old rebranded Marlin built post-WWII.
Let’s also be honest about what a furniture change really means - it’s simply a non-destructive furniture change. As much damage could and would typically happen during a detail strip and cleaning as would happen due to this furniture change, and frankly, this swap will likely mean the original wood will be better preserved than it would be if it remained attached to the rifle.
So for me, yup, if you have interest in an mlok railed levergun, then “modernize” the hell out of it. It’s a hell of a lot better that you rebuild it as you desire and make use of it than stick it in the back of the safe to rot away for lack of interest in its current aesthetic.