This picture is part no. 17665 but that is not the part you need if newton rings are your problem. There is an antinewton ring "filter" that goes over the condensor, which holds the film flat. I own the Valoy II, which uses this same setup. Later Valoy IIs actually used an ANR condensor.
Leica offered two aids to conquer Newton-rings:
-) NEWOO (a metal plate acting as distance holder, shown in the photo above)
-) NESOO (a glass plate with micro-roughened surface)