This tank was used from mid-1950 through the end of 1952, and on Model 165's from 1953-1959..
The "external" front tabs are welded on the outside of the tank.
The "long" rear tabs go most of the way down (actually up) into the tunnel.

This is most likely the 61000-47A tank, although the "A"suffix did not appear in the Spare Parts catalog until 1955. This was probably done (a little late) to differentiate the "old" and "new" on dealer's shelves.