I think the Oxy bottle statement is discussed on P143 of the Morgan Shacklady book.
Here is the bit.
The 30 June meeting discussing the general fitting of bob weights refers only to the MKV.
The Bob weight was initially trailed on the one off Spit MKIII. It was tested also on a single MKII airframe P7280 that features in a lot of the RAE tests.
So unless more evidence is provided there is nothing to confirm that bob weights were actually fitted to operational MKII's
Spin trials by RAE on the MKII and MKI (as posted earlier in this thread) generally considered spin characteristics as normal ... no real drama.
Here they are again !
Thanks Mig-3U more evidence that operational Spit II's wernt fitted with Bob weights.