Both A1670 and A1671 is 2th Generation and the screen is a 2th gen screen so it will fit.
The only thing that may be different enough to cause a issue between wifi model and cellular is the housing with the antennas and sim card slot causing issiues. With 12.9 2th gen the sim slot does not cause issues, can be left unplugged. Not sure about antennas but they tend to differentiate.