I did exactly that. Around 1980, I figured I needed a defensive shotgun more than a goose gun.
So, I worked over the 1950 field model Pop bought used and gave me in 1959 or so on a pheasant hunt into a "Serious" shotgun. I used it for 3 gun for a few years, hunted some deer with it and "retired" it to HD duty.
It still runs beautifully.
Mods were....
Cutting the barrel to 18" plus a little, mounting a ramp and bead. Long forcing cone.
Installing a Lyman Peep sans aperture.
Side Saddle and two shot Remington Mag extension w/ clamp.
Police wood stock and forearm with QD stud. Good Rempad, now in need of replacement.
Other than it's a 2 3/4" only gun, it's nigh optimum.
One caveat, this was not near new condition when I began the makeover. On a nigh perfect example of a first year of production 870, I'd leave it alone.
HTH...