0.201 is smaller than 1/8 BSP (which is 28 tpi anyway ).
1 BA is 0.2087 dia, so 0.201 would be truncated, but really being a 5.3 mm x 0.9mm pitch, thread it is 28.2 tpi
So not necessarily a good alternative.
The thread form may give an additional clue.
Is the mating thread 55, 60, or 47.5 degree?.. 55 is Whit form, so may be some BSW or BSF
7/32 is too big for 0.201.
60 will be Unified, or Metric
and 47.5 can only be British Association.
Of course it may a special, peculiar to that item (In the same way that Myford used 12 tpi on the later M series and the 7 Series.Mandrels )
Howard