I was on 543 Valiants at the end, before they were grounded, in 63/64.I only did one flight, I think out of Lossie, flying over the Kola Peninsula looking for subs leaving , once the ice had melted, from whatever the name of their base was near Murmansk
The 543 Reunion Dinner is on 7th May at Wyton- see the web site- [I'm not attending this year] suggest you write/contact one of the chaps organising it and ask that your request for info be read out and ask if anyone could give you any details.
Suspect most of the information is now so old and is no longer classified-in fact I think there are coach tours occasionally from N Norway to see what's left of the facilities there.