So, we as yet don't know if there was any Aviogenex/Britannia tie-up beyond 732 maintenance at Luton. Maybe the Englishman I heard back in 1987 was just a jobbing freelancer.
As an aside, was the Aviogenex 727 maintenance also entrusted to Britannia (I know the latter didn't operate them) or did JAT do the business in Belgrade ?
I was with Britannia at the time, and to the best of my knowledge there was no crew training input to Aviogenex