Whilst doing my porridge at HQSTC I had a letter addressed to 'The Chief technician'.......
The envelope was annotated 'I think this is for you chief' signed PSO to Chief Engineer.
On the CS grade thing, I used to attend meetings chaired by an SPTO; his opening statement was to inform us he was a wg cdr equivalent. Got into an ar*e kicking contest when I would not allow him onto a live range and so enjoyed it when he pompously referred to the orders only to find that as the specialist I executive command of that phase.