Smudge,
I told the original story out of synch with the actual chronology, so the events below actually took place before my swansong; therefore, a reverse irony is involved.
In those days there was a manpower shortage in the GE's section, which made it all the more galling when 'my' route was pinched by one of them.
No names here but he was a known self-seeker who left the service in '79, I believe.
Included in his many talents were his innate ability to start a fight in phone box, reporting sick when a duff trip came up, and causing one captain to question both his personal qualities and his technical abilities. This captain formally requested that Lyneham Ops should send somebody else to fix the job that he couldn't do, as he (the captain) had lost all confidence in the aforesaid GE. I drew the short straw - after I arrived and was briefed by the captain on what had taken place things were a little fraught between us two lineys. He resented my being called out to his job, while I had a similar sentiment towards him! As I mentioned earlier, when I discovered he had somehow wangled me out of my prized route, I was not entirely chuffed!
Due to the shortfall in GE numbers, several of us trade managers were checked out on other trades and possessed over-signing chits for basic-level coverage away from base - I would not pretend to have the same training as a GE in other than my own trade; that is why some SVC trips had a mix of several trades. Not necessarily an economic use of manpower or the defence budget, I know, but that was the situation - we just did what we had to do.
As for the entitlement to a 'Swan song' - there was no actual right to one, although there was an unwritten protocol in existence. I might add that I bear no malice towards GEs (well, perhaps one) - some of my best friends were such, one of whom I still correspond with almost 40 years on.