No 400 Mk 2 Fuzes ?

[ron3350]

I have these two fuzes that seem to be No 400 Mk2 Navy fuzes but one has a brass strip? where it should have threads for a cap.
Also the O has been drilled through for the fixing screw. Both 0 - 22 graduations.
MF /42 is Australian made but who is G.N.H. maker 9/42. (this may also be a No 401 fuze?).
Did some not use the threaded nose cap? All info is welcome.

 

[sgdbdr]

It could be just a minor mod. The EXACT marking of both fuzes after "N° 400 II" (II roman numbers, not 11) could explain.