I just did a side-by-side comparison of the 1895CB and 1895SS forearms.
The SS forarm is 1 1/2" longer and thicker than the CB forearm. It requires a different location for the dovetailed block that retains the forearm cap. Installation will require milling a dovetail under the barrel at the the location, and with this, you can use either forearm if you wish.
John