M336 = M1895 (post 1972) & M1895 = M336. A rose, by any other name, is still a rose.
The only real difference, on the modern M1895's, is that the ejection port and the magazine hole, in the receiver are larger to accommodate the bigger .45-70 rim.
In addition, the .45-70's mag tube has a "bump" or expanded area in it's sidewall, just forward of the receiver and opposite the loading gate, to allow the loading of the larger shells.
All aftermarket accessories and stocks are interchangeable,except for some minute differences in some models of M336's, like a different width hammer needing a different offset spur and the fact that Marlin stopped D/T-ing the sides of the receivers for peeps, so the proper top-mounted peep is required for those.