I worked on them for a couple of years. Overall I think it was a good aircraft, Corrosion has pretty much covered most of what they were like to work on, I'd forgotten about the inwards opening C window, you just had to be sure you slid the sun visor out of the way first, don't ask how I remember that one
I used to do a lot of NDT inspections on them, and of course being British they loved to x-ray things (all British aircraft I've worked on always had a lot of x-ray inspections), a couple I remember was the inspection on Wing Rib Zero that required access into the centre tank though the wing leading edge via a slide, easy enough to get into but a real pig to try and push yourself back out again !
Then there was the fuselage frame inspections where you would wallpaper fuselage with film from floor level to floor level, this used almost 100 meters of film that all had to be cut to size beforehand and then processed and viewed afterwards, this from start to finish would take about 4 days !
We never found anything on these inspections.
There were also more inspections on the wing lower skins back in the late 90s due to fuel contamination, I remember blending out some corrosion inside the wing, we kept going till we could see the hangar floor ! I believe several aircraft had complete wing skin replacements because of this. This is why you had to check the water drains every night.
They could be hard work but once you found your way around them they where pretty good to work on.