Smuj,
'Instruments to instruments' - I like that good sense of humour, he sounds like a good bloke.
Yep I guess the trade structures were/are a bit of a nightmare and that is without considering all the attentional Q-annotations. I must admit thought when I was serving you got used to it at a working level, I guess having a really good understanding of your own area and less so of others. I'd be surprised re the Pilot TG 21 tag, never heard that before. The O side is not organised by trade, aircrew were administered under the General Duties (GD) branch, believe still are. All Os below Wg Cdr belonged to their own branch specialisation eg Eng, Admin, Regt etc - all on a common pay scale. On promotion to Wg Cdr all transferred to the GD branch - believe that is still the case. As always, stand by to be corrected.