They were all based at MAN when I started there. There were two or three - 539s too if I recall.
When Dan Air 'merged' (sic) with BA we would occasionally see some odd registrations rotating through. YOP being one outstanding example. 😁
Noisy buggers but I learned a lot doing double engine changes on overtime and a few CSDS units which would wind themselves up like a banshee every now and again. Happy days.